Java中的使用及連接Redis數據庫(附源碼)
引言：
本文主要分享了Redis如何在IDEA中部署，運行；模擬加入Redis的操作；
目錄結構
1. 在IDEA中搭建Redis
1.1 創建項目
新建含有web的SpringBoot項目；
搭建項目參考：SpringBoot超詳細筆記：https://blog.csdn.net/weixin_42601136/article/details/108396511
1.2 添加依賴（不夠手動添加）
<dependencies> <!-- 1、 Jedis--> <dependency> <groupId>redis.clients</groupId> <artifactId>jedis</artifactId> <version>2.9.0</version> </dependency> <!-- 2、 Junit測試--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jdbc</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.1.2</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency></dependencies>
1.3 測試環境是否搭建成功
@Test public void test0() { //連接Redis Jedis jedis = new Jedis('127.0.0.1', 6379); //獲取kak String kaka = jedis.get('kak'); log.info(kaka); //創建datex String datex = jedis.set('datex', new Date().toString()); //獲取datex String datex1 = jedis.get('datex'); log.info(datex1); //關閉資源 jedis.close(); }
1.4 利用json存儲數據
@Test public void test1() { JedisPool pool = new JedisPool('127.0.0.1', 6379); Jedis jedis = pool.getResource(); Student student = new Student(1001, 'kak', 'man', '20'); String key = 'student'; String field = '1001'; String s = JsonUtils.objectToJson(student); String value = s; jedis.hset(key, field, value); String hget = jedis.hget(key, field); log.info(hget); jedis.close(); }
1.5 以byte的形式存儲對象
@Test public void test02() { //連接redis Jedis jedis = new Jedis('127.0.0.1', 6379); String key = 'Student'; Student value = new Student(1002, 'taotao', 'woman', '20'); //將key和value轉換為byte[] byte[] byteKey = SerializationUtils.serialize(key); byte[] byteValue = SerializationUtils.serialize(value); //將key和value存儲到redis中 jedis.set(byteKey, byteValue); //獲取value值 byte[] bytes = jedis.get(byteKey); //bytes反序列化為Student對象 Student stu = (Student) SerializationUtils.deserialize(bytes); System.out.println(stu); jedis.close(); }
1.6 加入連接池的操作
使用連接池操作，可以避免頻繁的創建和銷毀連接對象的消耗資源
@Test public void test3(){ //創建連接池 GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig(); poolConfig.setMaxTotal(100);//連接池中的最大活躍數 poolConfig.setMaxIdle(10);//最大空閑數 poolConfig.setMinIdle(5);//最小空閑數 poolConfig.setMaxWaitMillis(3000);//連接池空了，3000毫秒后沒有獲取Jedis對象，超時 //創建連接池 JedisPool pool = new JedisPool(poolConfig,'127.0.0.1',6379); //通過連接池獲取Jedis對象 Jedis resource = pool.getResource(); //獲取上面添加的datex String value = resource.get('datex'); log.info(value); resource.close(); }
1.7 管道操作
Redis的管道操作，執行一個命令需要先發送請求到Redis，需要經歷網絡延遲，Redis還需給客戶端一個響應；如果需要一次操作多個命令，可以通過管道，將命令放到客戶端的一個Pipeline中，之后一次將命令發送到服務端，服務端一次性返回到客戶端；
@Test public void test3(){ //創建連接池 GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig(); poolConfig.setMaxTotal(100);//連接池中的最大活躍數 poolConfig.setMaxIdle(10);//最大空閑數 poolConfig.setMinIdle(5);//最小空閑數 poolConfig.setMaxWaitMillis(3000);//連接池空了，3000毫秒后沒有獲取Jedis對象，超時 //創建連接池 JedisPool pool = new JedisPool(poolConfig,'127.0.0.1',6379); //通過連接池獲取Jedis對象 Jedis resource = pool.getResource(); //獲取上面添加的datex String value = resource.get('datex'); log.info(value); resource.close(); }
2. 從數據中查詢數據
場景：
將數據存入Redis中，避免訪問量過大，造成數據庫奔潰；2.1 生成實體類
@Test public void test3(){ //創建連接池 GenericObjectPoolConfig poolConfig = new GenericObjectPoolConfig(); poolConfig.setMaxTotal(100);//連接池中的最大活躍數 poolConfig.setMaxIdle(10);//最大空閑數 poolConfig.setMinIdle(5);//最小空閑數 poolConfig.setMaxWaitMillis(3000);//連接池空了，3000毫秒后沒有獲取Jedis對象，超時 //創建連接池 JedisPool pool = new JedisPool(poolConfig,'127.0.0.1',6379); //通過連接池獲取Jedis對象 Jedis resource = pool.getResource(); //獲取上面添加的datex String value = resource.get('datex'); log.info(value); resource.close(); }
2.2 生成實體模板類
package com.sx.kak.po;import java.util.ArrayList;import java.util.List;public class StudentExample { protected String orderByClause; protected boolean distinct; protected List<Criteria> oredCriteria; public StudentExample() { oredCriteria = new ArrayList<Criteria>(); } public void setOrderByClause(String orderByClause) { this.orderByClause = orderByClause; } public String getOrderByClause() { return orderByClause; } public void setDistinct(boolean distinct) { this.distinct = distinct; } public boolean isDistinct() { return distinct; } public List<Criteria> getOredCriteria() { return oredCriteria; } public void or(Criteria criteria) { oredCriteria.add(criteria); } public Criteria or() { Criteria criteria = createCriteriaInternal(); oredCriteria.add(criteria); return criteria; } public Criteria createCriteria() { Criteria criteria = createCriteriaInternal(); if (oredCriteria.size() == 0) { oredCriteria.add(criteria); } return criteria; } protected Criteria createCriteriaInternal() { Criteria criteria = new Criteria(); return criteria; } public void clear() { oredCriteria.clear(); orderByClause = null; distinct = false; } protected abstract static class GeneratedCriteria { protected List<Criterion> criteria; protected GeneratedCriteria() { super(); criteria = new ArrayList<Criterion>(); } public boolean isValid() { return criteria.size() > 0; } public List<Criterion> getAllCriteria() { return criteria; } public List<Criterion> getCriteria() { return criteria; } protected void addCriterion(String condition) { if (condition == null) {throw new RuntimeException('Value for condition cannot be null'); } criteria.add(new Criterion(condition)); } protected void addCriterion(String condition, Object value, String property) { if (value == null) {throw new RuntimeException('Value for ' + property + ' cannot be null'); } criteria.add(new Criterion(condition, value)); } protected void addCriterion(String condition, Object value1, Object value2, String property) { if (value1 == null || value2 == null) {throw new RuntimeException('Between values for ' + property + ' cannot be null'); } criteria.add(new Criterion(condition, value1, value2)); } public Criteria andIdIsNull() { addCriterion('id is null'); return (Criteria) this; } public Criteria andIdIsNotNull() { addCriterion('id is not null'); return (Criteria) this; } public Criteria andIdEqualTo(Integer value) { addCriterion('id =', value, 'id'); return (Criteria) this; } public Criteria andIdNotEqualTo(Integer value) { addCriterion('id <>', value, 'id'); return (Criteria) this; } public Criteria andIdGreaterThan(Integer value) { addCriterion('id >', value, 'id'); return (Criteria) this; } public Criteria andIdGreaterThanOrEqualTo(Integer value) { addCriterion('id >=', value, 'id'); return (Criteria) this; } public Criteria andIdLessThan(Integer value) { addCriterion('id <', value, 'id'); return (Criteria) this; } public Criteria andIdLessThanOrEqualTo(Integer value) { addCriterion('id <=', value, 'id'); return (Criteria) this; } public Criteria andIdIn(List<Integer> values) { addCriterion('id in', values, 'id'); return (Criteria) this; } public Criteria andIdNotIn(List<Integer> values) { addCriterion('id not in', values, 'id'); return (Criteria) this; } public Criteria andIdBetween(Integer value1, Integer value2) { addCriterion('id between', value1, value2, 'id'); return (Criteria) this; } public Criteria andIdNotBetween(Integer value1, Integer value2) { addCriterion('id not between', value1, value2, 'id'); return (Criteria) this; } public Criteria andNameIsNull() { addCriterion('NAME is null'); return (Criteria) this; } public Criteria andNameIsNotNull() { addCriterion('NAME is not null'); return (Criteria) this; } public Criteria andNameEqualTo(String value) { addCriterion('NAME =', value, 'name'); return (Criteria) this; } public Criteria andNameNotEqualTo(String value) { addCriterion('NAME <>', value, 'name'); return (Criteria) this; } public Criteria andNameGreaterThan(String value) { addCriterion('NAME >', value, 'name'); return (Criteria) this; } public Criteria andNameGreaterThanOrEqualTo(String value) { addCriterion('NAME >=', value, 'name'); return (Criteria) this; } public Criteria andNameLessThan(String value) { addCriterion('NAME <', value, 'name'); return (Criteria) this; } public Criteria andNameLessThanOrEqualTo(String value) { addCriterion('NAME <=', value, 'name'); return (Criteria) this; } public Criteria andNameLike(String value) { addCriterion('NAME like', value, 'name'); return (Criteria) this; } public Criteria andNameNotLike(String value) { addCriterion('NAME not like', value, 'name'); return (Criteria) this; } public Criteria andNameIn(List<String> values) { addCriterion('NAME in', values, 'name'); return (Criteria) this; } public Criteria andNameNotIn(List<String> values) { addCriterion('NAME not in', values, 'name'); return (Criteria) this; } public Criteria andNameBetween(String value1, String value2) { addCriterion('NAME between', value1, value2, 'name'); return (Criteria) this; } public Criteria andNameNotBetween(String value1, String value2) { addCriterion('NAME not between', value1, value2, 'name'); return (Criteria) this; } public Criteria andSexIsNull() { addCriterion('sex is null'); return (Criteria) this; } public Criteria andSexIsNotNull() { addCriterion('sex is not null'); return (Criteria) this; } public Criteria andSexEqualTo(String value) { addCriterion('sex =', value, 'sex'); return (Criteria) this; } public Criteria andSexNotEqualTo(String value) { addCriterion('sex <>', value, 'sex'); return (Criteria) this; } public Criteria andSexGreaterThan(String value) { addCriterion('sex >', value, 'sex'); return (Criteria) this; } public Criteria andSexGreaterThanOrEqualTo(String value) { addCriterion('sex >=', value, 'sex'); return (Criteria) this; } public Criteria andSexLessThan(String value) { addCriterion('sex <', value, 'sex'); return (Criteria) this; } public Criteria andSexLessThanOrEqualTo(String value) { addCriterion('sex <=', value, 'sex'); return (Criteria) this; } public Criteria andSexLike(String value) { addCriterion('sex like', value, 'sex'); return (Criteria) this; } public Criteria andSexNotLike(String value) { addCriterion('sex not like', value, 'sex'); return (Criteria) this; } public Criteria andSexIn(List<String> values) { addCriterion('sex in', values, 'sex'); return (Criteria) this; } public Criteria andSexNotIn(List<String> values) { addCriterion('sex not in', values, 'sex'); return (Criteria) this; } public Criteria andSexBetween(String value1, String value2) { addCriterion('sex between', value1, value2, 'sex'); return (Criteria) this; } public Criteria andSexNotBetween(String value1, String value2) { addCriterion('sex not between', value1, value2, 'sex'); return (Criteria) this; } public Criteria andAgeIsNull() { addCriterion('age is null'); return (Criteria) this; } public Criteria andAgeIsNotNull() { addCriterion('age is not null'); return (Criteria) this; } public Criteria andAgeEqualTo(String value) { addCriterion('age =', value, 'age'); return (Criteria) this; } public Criteria andAgeNotEqualTo(String value) { addCriterion('age <>', value, 'age'); return (Criteria) this; } public Criteria andAgeGreaterThan(String value) { addCriterion('age >', value, 'age'); return (Criteria) this; } public Criteria andAgeGreaterThanOrEqualTo(String value) { addCriterion('age >=', value, 'age'); return (Criteria) this; } public Criteria andAgeLessThan(String value) { addCriterion('age <', value, 'age'); return (Criteria) this; } public Criteria andAgeLessThanOrEqualTo(String value) { addCriterion('age <=', value, 'age'); return (Criteria) this; } public Criteria andAgeLike(String value) { addCriterion('age like', value, 'age'); return (Criteria) this; } public Criteria andAgeNotLike(String value) { addCriterion('age not like', value, 'age'); return (Criteria) this; } public Criteria andAgeIn(List<String> values) { addCriterion('age in', values, 'age'); return (Criteria) this; } public Criteria andAgeNotIn(List<String> values) { addCriterion('age not in', values, 'age'); return (Criteria) this; } public Criteria andAgeBetween(String value1, String value2) { addCriterion('age between', value1, value2, 'age'); return (Criteria) this; } public Criteria andAgeNotBetween(String value1, String value2) { addCriterion('age not between', value1, value2, 'age'); return (Criteria) this; } } public static class Criteria extends GeneratedCriteria { protected Criteria() { super(); } } public static class Criterion { private String condition; private Object value; private Object secondValue; private boolean noValue; private boolean singleValue; private boolean betweenValue; private boolean listValue; private String typeHandler; public String getCondition() { return condition; } public Object getValue() { return value; } public Object getSecondValue() { return secondValue; } public boolean isNoValue() { return noValue; } public boolean isSingleValue() { return singleValue; } public boolean isBetweenValue() { return betweenValue; } public boolean isListValue() { return listValue; } public String getTypeHandler() { return typeHandler; } protected Criterion(String condition) { super(); this.condition = condition; this.typeHandler = null; this.noValue = true; } protected Criterion(String condition, Object value, String typeHandler) { super(); this.condition = condition; this.value = value; this.typeHandler = typeHandler; if (value instanceof List<?>) {this.listValue = true; } else {this.singleValue = true; } } protected Criterion(String condition, Object value) { this(condition, value, null); } protected Criterion(String condition, Object value, Object secondValue, String typeHandler) { super(); this.condition = condition; this.value = value; this.secondValue = secondValue; this.typeHandler = typeHandler; this.betweenValue = true; } protected Criterion(String condition, Object value, Object secondValue) { this(condition, value, secondValue, null); } }}
2.3 生成studentMapper.java
package com.sx.kak.po;import java.util.ArrayList;import java.util.List;public class StudentExample { protected String orderByClause; protected boolean distinct; protected List<Criteria> oredCriteria; public StudentExample() { oredCriteria = new ArrayList<Criteria>(); } public void setOrderByClause(String orderByClause) { this.orderByClause = orderByClause; } public String getOrderByClause() { return orderByClause; } public void setDistinct(boolean distinct) { this.distinct = distinct; } public boolean isDistinct() { return distinct; } public List<Criteria> getOredCriteria() { return oredCriteria; } public void or(Criteria criteria) { oredCriteria.add(criteria); } public Criteria or() { Criteria criteria = createCriteriaInternal(); oredCriteria.add(criteria); return criteria; } public Criteria createCriteria() { Criteria criteria = createCriteriaInternal(); if (oredCriteria.size() == 0) { oredCriteria.add(criteria); } return criteria; } protected Criteria createCriteriaInternal() { Criteria criteria = new Criteria(); return criteria; } public void clear() { oredCriteria.clear(); orderByClause = null; distinct = false; } protected abstract static class GeneratedCriteria { protected List<Criterion> criteria; protected GeneratedCriteria() { super(); criteria = new ArrayList<Criterion>(); } public boolean isValid() { return criteria.size() > 0; } public List<Criterion> getAllCriteria() { return criteria; } public List<Criterion> getCriteria() { return criteria; } protected void addCriterion(String condition) { if (condition == null) {throw new RuntimeException('Value for condition cannot be null'); } criteria.add(new Criterion(condition)); } protected void addCriterion(String condition, Object value, String property) { if (value == null) {throw new RuntimeException('Value for ' + property + ' cannot be null'); } criteria.add(new Criterion(condition, value)); } protected void addCriterion(String condition, Object value1, Object value2, String property) { if (value1 == null || value2 == null) {throw new RuntimeException('Between values for ' + property + ' cannot be null'); } criteria.add(new Criterion(condition, value1, value2)); } public Criteria andIdIsNull() { addCriterion('id is null'); return (Criteria) this; } public Criteria andIdIsNotNull() { addCriterion('id is not null'); return (Criteria) this; } public Criteria andIdEqualTo(Integer value) { addCriterion('id =', value, 'id'); return (Criteria) this; } public Criteria andIdNotEqualTo(Integer value) { addCriterion('id <>', value, 'id'); return (Criteria) this; } public Criteria andIdGreaterThan(Integer value) { addCriterion('id >', value, 'id'); return (Criteria) this; } public Criteria andIdGreaterThanOrEqualTo(Integer value) { addCriterion('id >=', value, 'id'); return (Criteria) this; } public Criteria andIdLessThan(Integer value) { addCriterion('id <', value, 'id'); return (Criteria) this; } public Criteria andIdLessThanOrEqualTo(Integer value) { addCriterion('id <=', value, 'id'); return (Criteria) this; } public Criteria andIdIn(List<Integer> values) { addCriterion('id in', values, 'id'); return (Criteria) this; } public Criteria andIdNotIn(List<Integer> values) { addCriterion('id not in', values, 'id'); return (Criteria) this; } public Criteria andIdBetween(Integer value1, Integer value2) { addCriterion('id between', value1, value2, 'id'); return (Criteria) this; } public Criteria andIdNotBetween(Integer value1, Integer value2) { addCriterion('id not between', value1, value2, 'id'); return (Criteria) this; } public Criteria andNameIsNull() { addCriterion('NAME is null'); return (Criteria) this; } public Criteria andNameIsNotNull() { addCriterion('NAME is not null'); return (Criteria) this; } public Criteria andNameEqualTo(String value) { addCriterion('NAME =', value, 'name'); return (Criteria) this; } public Criteria andNameNotEqualTo(String value) { addCriterion('NAME <>', value, 'name'); return (Criteria) this; } public Criteria andNameGreaterThan(String value) { addCriterion('NAME >', value, 'name'); return (Criteria) this; } public Criteria andNameGreaterThanOrEqualTo(String value) { addCriterion('NAME >=', value, 'name'); return (Criteria) this; } public Criteria andNameLessThan(String value) { addCriterion('NAME <', value, 'name'); return (Criteria) this; } public Criteria andNameLessThanOrEqualTo(String value) { addCriterion('NAME <=', value, 'name'); return (Criteria) this; } public Criteria andNameLike(String value) { addCriterion('NAME like', value, 'name'); return (Criteria) this; } public Criteria andNameNotLike(String value) { addCriterion('NAME not like', value, 'name'); return (Criteria) this; } public Criteria andNameIn(List<String> values) { addCriterion('NAME in', values, 'name'); return (Criteria) this; } public Criteria andNameNotIn(List<String> values) { addCriterion('NAME not in', values, 'name'); return (Criteria) this; } public Criteria andNameBetween(String value1, String value2) { addCriterion('NAME between', value1, value2, 'name'); return (Criteria) this; } public Criteria andNameNotBetween(String value1, String value2) { addCriterion('NAME not between', value1, value2, 'name'); return (Criteria) this; } public Criteria andSexIsNull() { addCriterion('sex is null'); return (Criteria) this; } public Criteria andSexIsNotNull() { addCriterion('sex is not null'); return (Criteria) this; } public Criteria andSexEqualTo(String value) { addCriterion('sex =', value, 'sex'); return (Criteria) this; } public Criteria andSexNotEqualTo(String value) { addCriterion('sex <>', value, 'sex'); return (Criteria) this; } public Criteria andSexGreaterThan(String value) { addCriterion('sex >', value, 'sex'); return (Criteria) this; } public Criteria andSexGreaterThanOrEqualTo(String value) { addCriterion('sex >=', value, 'sex'); return (Criteria) this; } public Criteria andSexLessThan(String value) { addCriterion('sex <', value, 'sex'); return (Criteria) this; } public Criteria andSexLessThanOrEqualTo(String value) { addCriterion('sex <=', value, 'sex'); return (Criteria) this; } public Criteria andSexLike(String value) { addCriterion('sex like', value, 'sex'); return (Criteria) this; } public Criteria andSexNotLike(String value) { addCriterion('sex not like', value, 'sex'); return (Criteria) this; } public Criteria andSexIn(List<String> values) { addCriterion('sex in', values, 'sex'); return (Criteria) this; } public Criteria andSexNotIn(List<String> values) { addCriterion('sex not in', values, 'sex'); return (Criteria) this; } public Criteria andSexBetween(String value1, String value2) { addCriterion('sex between', value1, value2, 'sex'); return (Criteria) this; } public Criteria andSexNotBetween(String value1, String value2) { addCriterion('sex not between', value1, value2, 'sex'); return (Criteria) this; } public Criteria andAgeIsNull() { addCriterion('age is null'); return (Criteria) this; } public Criteria andAgeIsNotNull() { addCriterion('age is not null'); return (Criteria) this; } public Criteria andAgeEqualTo(String value) { addCriterion('age =', value, 'age'); return (Criteria) this; } public Criteria andAgeNotEqualTo(String value) { addCriterion('age <>', value, 'age'); return (Criteria) this; } public Criteria andAgeGreaterThan(String value) { addCriterion('age >', value, 'age'); return (Criteria) this; } public Criteria andAgeGreaterThanOrEqualTo(String value) { addCriterion('age >=', value, 'age'); return (Criteria) this; } public Criteria andAgeLessThan(String value) { addCriterion('age <', value, 'age'); return (Criteria) this; } public Criteria andAgeLessThanOrEqualTo(String value) { addCriterion('age <=', value, 'age'); return (Criteria) this; } public Criteria andAgeLike(String value) { addCriterion('age like', value, 'age'); return (Criteria) this; } public Criteria andAgeNotLike(String value) { addCriterion('age not like', value, 'age'); return (Criteria) this; } public Criteria andAgeIn(List<String> values) { addCriterion('age in', values, 'age'); return (Criteria) this; } public Criteria andAgeNotIn(List<String> values) { addCriterion('age not in', values, 'age'); return (Criteria) this; } public Criteria andAgeBetween(String value1, String value2) { addCriterion('age between', value1, value2, 'age'); return (Criteria) this; } public Criteria andAgeNotBetween(String value1, String value2) { addCriterion('age not between', value1, value2, 'age'); return (Criteria) this; } } public static class Criteria extends GeneratedCriteria { protected Criteria() { super(); } } public static class Criterion { private String condition; private Object value; private Object secondValue; private boolean noValue; private boolean singleValue; private boolean betweenValue; private boolean listValue; private String typeHandler; public String getCondition() { return condition; } public Object getValue() { return value; } public Object getSecondValue() { return secondValue; } public boolean isNoValue() { return noValue; } public boolean isSingleValue() { return singleValue; } public boolean isBetweenValue() { return betweenValue; } public boolean isListValue() { return listValue; } public String getTypeHandler() { return typeHandler; } protected Criterion(String condition) { super(); this.condition = condition; this.typeHandler = null; this.noValue = true; } protected Criterion(String condition, Object value, String typeHandler) { super(); this.condition = condition; this.value = value; this.typeHandler = typeHandler; if (value instanceof List<?>) {this.listValue = true; } else {this.singleValue = true; } } protected Criterion(String condition, Object value) { this(condition, value, null); } protected Criterion(String condition, Object value, Object secondValue, String typeHandler) { super(); this.condition = condition; this.value = value; this.secondValue = secondValue; this.typeHandler = typeHandler; this.betweenValue = true; } protected Criterion(String condition, Object value, Object secondValue) { this(condition, value, secondValue, null); } }}
2.4 生成StudentMapper.xml
<?xml version='1.0' encoding='UTF-8' ?><!DOCTYPE mapper PUBLIC '-//mybatis.org//DTD Mapper 3.0//EN' 'http://mybatis.org/dtd/mybatis-3-mapper.dtd' ><mapper namespace='com.sx.kak.mapper.StudentMapper' > <resultMap type='com.sx.kak.po.Student' > <id column='id' property='id' jdbcType='INTEGER' /> <result column='NAME' property='name' jdbcType='VARCHAR' /> <result column='sex' property='sex' jdbcType='VARCHAR' /> <result column='age' property='age' jdbcType='VARCHAR' /> </resultMap> <sql > <where > <foreach collection='oredCriteria' item='criteria' separator='or' > <if test='criteria.valid' > <trim prefix='(' suffix=')' prefixOverrides='and' > <foreach collection='criteria.criteria' item='criterion' > <choose ><when test='criterion.noValue' > and ${criterion.condition}</when><when test='criterion.singleValue' > and ${criterion.condition} #{criterion.value}</when><when test='criterion.betweenValue' > and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}</when><when test='criterion.listValue' > and ${criterion.condition} <foreach collection='criterion.value' item='listItem' open='(' close=')' separator=',' > #{listItem} </foreach></when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql > <where > <foreach collection='example.oredCriteria' item='criteria' separator='or' > <if test='criteria.valid' > <trim prefix='(' suffix=')' prefixOverrides='and' > <foreach collection='criteria.criteria' item='criterion' > <choose ><when test='criterion.noValue' > and ${criterion.condition}</when><when test='criterion.singleValue' > and ${criterion.condition} #{criterion.value}</when><when test='criterion.betweenValue' > and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}</when><when test='criterion.listValue' > and ${criterion.condition} <foreach collection='criterion.value' item='listItem' open='(' close=')' separator=',' > #{listItem} </foreach></when> </choose> </foreach> </trim> </if> </foreach> </where> </sql> <sql > id, NAME, sex, age </sql> <select resultMap='BaseResultMap' parameterType='com.sx.kak.po.StudentExample' > select <if test='distinct' > distinct </if> <include refid='Base_Column_List' /> from student <if test='_parameter != null' > <include refid='Example_Where_Clause' /> </if> <if test='orderByClause != null' > order by ${orderByClause} </if> </select> <select resultMap='BaseResultMap' parameterType='java.lang.Integer' > select <include refid='Base_Column_List' /> from student where id = #{id,jdbcType=INTEGER} </select> <delete parameterType='java.lang.Integer' > delete from student where id = #{id,jdbcType=INTEGER} </delete> <delete parameterType='com.sx.kak.po.StudentExample' > delete from student <if test='_parameter != null' > <include refid='Example_Where_Clause' /> </if> </delete> <insert parameterType='com.sx.kak.po.Student' > insert into student (id, NAME, sex, age) values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, #{sex,jdbcType=VARCHAR}, #{age,jdbcType=VARCHAR}) </insert> <insert parameterType='com.sx.kak.po.Student' > insert into student <trim prefix='(' suffix=')' suffixOverrides=',' > <if test='id != null' > id, </if> <if test='name != null' > NAME, </if> <if test='sex != null' > sex, </if> <if test='age != null' > age, </if> </trim> <trim prefix='values (' suffix=')' suffixOverrides=',' > <if test='id != null' > #{id,jdbcType=INTEGER}, </if> <if test='name != null' > #{name,jdbcType=VARCHAR}, </if> <if test='sex != null' > #{sex,jdbcType=VARCHAR}, </if> <if test='age != null' > #{age,jdbcType=VARCHAR}, </if> </trim> </insert> <select parameterType='com.sx.kak.po.StudentExample' resultType='java.lang.Integer' > select count(*) from student <if test='_parameter != null' > <include refid='Example_Where_Clause' /> </if> </select> <update parameterType='map' > update student <set > <if test='record.id != null' > id = #{record.id,jdbcType=INTEGER}, </if> <if test='record.name != null' > NAME = #{record.name,jdbcType=VARCHAR}, </if> <if test='record.sex != null' > sex = #{record.sex,jdbcType=VARCHAR}, </if> <if test='record.age != null' > age = #{record.age,jdbcType=VARCHAR}, </if> </set> <if test='_parameter != null' > <include refid='Update_By_Example_Where_Clause' /> </if> </update> <update parameterType='map' > update student set id = #{record.id,jdbcType=INTEGER}, NAME = #{record.name,jdbcType=VARCHAR}, sex = #{record.sex,jdbcType=VARCHAR}, age = #{record.age,jdbcType=VARCHAR} <if test='_parameter != null' > <include refid='Update_By_Example_Where_Clause' /> </if> </update> <update parameterType='com.sx.kak.po.Student' > update student <set > <if test='name != null' > NAME = #{name,jdbcType=VARCHAR}, </if> <if test='sex != null' > sex = #{sex,jdbcType=VARCHAR}, </if> <if test='age != null' > age = #{age,jdbcType=VARCHAR}, </if> </set> where id = #{id,jdbcType=INTEGER} </update> <update parameterType='com.sx.kak.po.Student' > update student set NAME = #{name,jdbcType=VARCHAR}, sex = #{sex,jdbcType=VARCHAR}, age = #{age,jdbcType=VARCHAR} where id = #{id,jdbcType=INTEGER} </update></mapper>
2.5 編寫application.yml
server: port: 8080spring: datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/db0711?characterEncoding=utf8&serverTimezone=UTC username: root password: rootmybatis: type-aliases-package: po mapper-locations: classpath:mapping/*.xml
2.6 編寫JsonUtils工具類
package com.sx.kak.utils;import java.util.List;import com.fasterxml.jackson.core.JsonProcessingException;import com.fasterxml.jackson.databind.JavaType;import com.fasterxml.jackson.databind.ObjectMapper;public class JsonUtils { // 定義jackson對象 private static final ObjectMapper MAPPER = new ObjectMapper(); /** * 將對象轉換成json字符串。 * <p>Title: pojoToJson</p> * <p>Description: </p> * @param data * @return */ public static String objectToJson(Object data) { try {String string = MAPPER.writeValueAsString(data);return string;} catch (JsonProcessingException e) {e.printStackTrace();} return null; } /** * 將json結果集轉化為對象 * * @param jsonData json數據 * @param clazz 對象中的object類型 * @return */ public static <T> T jsonToPojo(String jsonData, Class<T> beanType) { try { T t = MAPPER.readValue(jsonData, beanType); return t; } catch (Exception e) { e.printStackTrace(); } return null; } /** * 將json數據轉換成pojo對象list * <p>Title: jsonToList</p> * <p>Description: </p> * @param jsonData * @param beanType * @return */ public static <T>List<T> jsonToList(String jsonData, Class<T> beanType) { JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType); try { List<T> list = MAPPER.readValue(jsonData, javaType); return list;} catch (Exception e) {e.printStackTrace();} return null; }}
2.7 編寫RedisUtils工具類
package com.sx.kak.utils;import java.util.List;import com.fasterxml.jackson.core.JsonProcessingException;import com.fasterxml.jackson.databind.JavaType;import com.fasterxml.jackson.databind.ObjectMapper;public class JsonUtils { // 定義jackson對象 private static final ObjectMapper MAPPER = new ObjectMapper(); /** * 將對象轉換成json字符串。 * <p>Title: pojoToJson</p> * <p>Description: </p> * @param data * @return */ public static String objectToJson(Object data) { try {String string = MAPPER.writeValueAsString(data);return string;} catch (JsonProcessingException e) {e.printStackTrace();} return null; } /** * 將json結果集轉化為對象 * * @param jsonData json數據 * @param clazz 對象中的object類型 * @return */ public static <T> T jsonToPojo(String jsonData, Class<T> beanType) { try { T t = MAPPER.readValue(jsonData, beanType); return t; } catch (Exception e) { e.printStackTrace(); } return null; } /** * 將json數據轉換成pojo對象list * <p>Title: jsonToList</p> * <p>Description: </p> * @param jsonData * @param beanType * @return */ public static <T>List<T> jsonToList(String jsonData, Class<T> beanType) { JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType); try { List<T> list = MAPPER.readValue(jsonData, javaType); return list;} catch (Exception e) {e.printStackTrace();} return null; }}
2.8 編寫RedisUtils工具類的實現類
package com.sx.kak.utils;import redis.clients.jedis.Jedis;/** * Created by Kak on 2020/9/17. */public class SingleTonRedisUtil implements RedisUtils{ private Jedis jedis; public SingleTonRedisUtil(Jedis jedis){ this.jedis = jedis; } @Override public void hset(String key, String filed, String value) { jedis.hset(key, filed, value); } @Override public String hget(String key, String field) { return jedis.hget(key, field); }}
2.9 配置初始化文件
package com.sx.kak.config;import com.sx.kak.utils.SingleTonRedisUtil;import org.springframework.beans.factory.annotation.Qualifier;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;import redis.clients.jedis.Jedis;/** * Created by Kak on 2020/9/17. */@Configurationpublic class RedisConfig { @Bean public SingleTonRedisUtil singleTonRedisUtil(@Qualifier('jedis') Jedis jedis){ SingleTonRedisUtil singleTonRedisUtil = new SingleTonRedisUtil(jedis); return singleTonRedisUtil; } @Bean(name = 'jedis') public Jedis getJedis(){ Jedis jedis = new Jedis('127.0.0.1',6379); return jedis; }}
2.10 配置StudentService.java
package com.sx.kak.service;import com.sx.kak.po.Student;import java.util.List;/** * Created by Kak on 2020/9/17. */public interface StudentService { public List<Student> findAllStudent();}
2.11 配置StudentServiceImpl.java
package com.sx.kak.service.serviceImpl;import com.sx.kak.mapper.StudentMapper;import com.sx.kak.po.Student;import com.sx.kak.po.StudentExample;import com.sx.kak.service.StudentService;import com.sx.kak.utils.JsonUtils;import com.sx.kak.utils.SingleTonRedisUtil;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import java.util.List;/** * Created by Kak on 2020/9/17. */@Service@Slf4jpublic class StudentServiceImpl implements StudentService { @Autowired(required = false) private StudentMapper studentMapper; //注入自定義的redis工具 @Autowired private SingleTonRedisUtil redisUtil; @Override public List<Student> findAllStudent() { //獲取redis中存出的json字符串 String student = redisUtil.hget('student', '0'); if(student!=null){ log.info('get student from redis'); //json對象，封裝的對象類型 List<Student> students = JsonUtils.jsonToList(student, Student.class); return students; } //創建查詢模板對象 StudentExample studentExample = new StudentExample(); List<Student> students = studentMapper.selectByExample(studentExample); log.info('get student from db'); try{ //將查詢的集合轉化為json字符串 String s = JsonUtils.objectToJson(students); //放入redis中 redisUtil.hset('student','0',s); log.info('set data to redis'); }catch (Exception ex){ log.info(ex.getMessage()); } return students; }}
2.12 編寫全查展示頁面
<!DOCTYPE html><html lang='en' xmlns:th='http://www.thymeleaf.org'><head> <meta charset='UTF-8'/> <title>學生全查頁面</title></head><body><div id='findAll'> <table> <tr> <th>ID</th> <th>NAME</th> <th>SEX</th> <th>AGE</th> <th>Action</th> </tr> <tr th:each='s:${students}'> <td th:text='${s.id}'></td> <td th:text='${s.name}'></td> <td th:text='${s.sex}'></td> <td th:text='${s.age}'></td> </tr> </table></div></body></html>
2.13 編寫StudentController
package com.sx.kak.Controller;import com.sx.kak.po.Student;import com.sx.kak.service.StudentService;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController;import java.util.List;/** * Created by Kak on 2020/9/17. */@Controllerpublic class StudentController { @Autowired(required = false) private StudentService studentService; @RequestMapping('/findStudent') public String findAllStu(Model model){ List<Student> allStudent = studentService.findAllStudent(); model.addAttribute('students',allStudent); return 'showAllStudent'; }}
3. 結果
從打印出的日志可以看出，第一次訪問是從數據庫得到數據，然后存入redis中
第二次直接從redis中獲取
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