jdbcTemplate小用总结

一、queryForList重写

     public List<Map<String, Object>> queryForList(String tablename, Map<String, String> param) {//TODO valid @tablename is nullStringBuilder sql = new StringBuilder("select sys_id  from "); sql.append(tablename);sql.append(" where sys_deleted = ?  ");List<String> valueList = new ArrayList<>(); valueList.add("0");if (!CollectionUtils.isEmpty(param)) {for(Map.Entry<String, String> paramSet:param.entrySet()) {sql.append(" and ").append(paramSet.getKey()).append(" = ? ");valueList.add(paramSet.getValue());}}String[] params = params = (String[])valueList.toArray(new String[valueList.size()]);return jdbcTemplate.queryForList(sql.toString(), params);  }  
}

注意：

所有查询必需是db表中字段，包括sys_id

2、能批处理不要单个处理，原理及原因：

(1)MySQL批量SQL插入性能优化 - 唐成勇 - SegmentFault 思否
https://segmentfault.com/a/1190000008890065

参考：

spring boot(6)-JdbcTemplate访问数据库 - CSDN博客
https://blog.csdn.net/wangb_java/article/details/72789915

ArrayList和数组间的相互转换
http://wanglihu.iteye.com/blog/243238

二、batchUpdate方法使用

需求：business表中的若干数据，需要把这些数据的id，随机的选一条，插入到a,b,c d这些表中的business列中

package cn.partner4java.dao;  import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Random;import org.apache.commons.lang3.RandomStringUtils;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.jdbc.core.BatchPreparedStatementSetter;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.transaction.annotation.Transactional;  /** 
* @author partner4java 
* 使用JDBC Template处理数据 
http://irfen.me/use-jdbc-template-manipulation-data/
* 
*/ 
public class HelloDaoImpl extends JdbcDaoSupport {  @Transactional  public void saveHello(String tablename){  List<String> listBusiness = getBusinessId();final List<Object[]> updateParams = new ArrayList<Object[]>();List<Map<String, Object>> cis = this.getJdbcTemplate().queryForList("select * from "+tablename); for (Map<String, Object> map : cis) {String cisysid = (String) map.get("sys_id");java.util.Random random=new java.util.Random();// 定义随机类int result=random.nextInt(listBusiness.size());// String businessid = listBusiness.get(result);updateParams.add(new Object[] { businessid, cisysid });}addCIs(tablename, updateParams);}public void addCIs(String tablename , final List<Object[]> updateParams )  {  String sql = "update "+ tablename + " set cmdb_ci_business=? where sys_id=?";  this.getJdbcTemplate().batchUpdate(sql, new BatchPreparedStatementSetter()  {  @Override  public int getBatchSize() {  return updateParams.size();  }  @Overridepublic void setValues(PreparedStatement ps, int i) throws SQLException {Object[] args = updateParams.get(i);ps.setString(1, (String) args[0]);ps.setString(2, (String) args[1]);}  });  } private List<String> getBusinessId() {List<String> listBusiness = new ArrayList<>();List<Map<String, Object>> cis = this.getJdbcTemplate().queryForList("select * from cmdb_ci_business"); for (Map<String, Object> map : cis) {listBusiness.add((String)map.get("sys_id"));}return listBusiness;}  public static void main(String[] args) {ApplicationContext ac = new ClassPathXmlApplicationContext("app-context.xml");  HelloDaoImpl helloDao = (HelloDaoImpl) ac.getBean("helloDao");  List<String> tableList = new ArrayList<>();tableList.add("a");tableList.add("b");tableList.add("c");tableList.add("d");tableList.add("e");tableList.add("f");tableList.add("g");tableList.add("h");for (String table : tableList) {helloDao.saveHello(table); }}
}

app.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="  http://www.springframework.org/schema/beans  http://www.springframework.org/schema/beans/spring-beans.xsd  http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx.xsd  http://www.springframework.org/schema/aop  http://www.springframework.org/schema/aop/spring-aop.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsd"><bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"init-method="init" destroy-method="close"><property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://10.128.106.78:3306/itsm?useSSL=false" /><property name="username" value="root" /><property name="password" value="OneITSM" /></bean><bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"><constructor-arg><ref bean="dataSource" /></constructor-arg></bean><bean id="transactionManager"class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource" /></bean><tx:annotation-driven transaction-manager="transactionManager" /><aop:aspectj-autoproxy /><!-- <context:component-scan base-package="cn.partner4java.dao" /><context:component-scan base-package="cn.partner4java.myptm" /> --><bean id="helloDao" class="cn.partner4java.dao.HelloDaoImpl"><property name="jdbcTemplate"><ref bean="jdbcTemplate"/></property></bean><!-- <bean id="user" class="springjdbc.pojo.User"><property name="dao"><ref bean="userDAO"/></property></bean> -->
</beans>

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.paymoon</groupId><artifactId>simplebusiness</artifactId><packaging>war</packaging><version>0.0.1-SNAPSHOT</version><name>simplebusiness Maven Webapp</name><url>http://maven.apache.org</url><properties><project.build.sourceEncoding>UTF-8</project.build.sourceEncoding></properties><dependencies><dependency><groupId>com.paymoon.basic</groupId><artifactId>basic-commons</artifactId><version>0.0.1-SNAPSHOT</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.39</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.0.29</version></dependency></dependencies><build><plugins><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-gpg-plugin</artifactId><version>1.4</version><executions><execution><id>sign-artifacts</id><phase>verify</phase><goals><goal>sign</goal></goals></execution></executions></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-release-plugin</artifactId><version>2.2.2</version><dependencies><dependency><groupId>org.apache.maven.plugins</groupId><artifactId>maven-scm-plugin</artifactId><version>1.8.1</version></dependency></dependencies></plugin><plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-compiler-plugin</artifactId><version>3.2</version><configuration><source>1.8</source><target>1.8</target></configuration></plugin></plugins></build>
</project>

划重点

1 int result=random.nextInt(listBusiness.size());// String businessid = listBusiness.get(result)
2 update的使用

String sql = "update "+ tablename + " set cmdb_ci_business=? where sys_id=?";  this.getJdbcTemplate().batchUpdate(sql, new BatchPreparedStatementSetter()  {  @Override  public int getBatchSize() {  return updateParams.size();  }  @Overridepublic void setValues(PreparedStatement ps, int i) throws SQLException {Object[] args = updateParams.get(i);ps.setString(1, (String) args[0]);ps.setString(2, (String) args[1]);}