DbUtils与Ext DbUtils实战-优快云博客

代码使用案例：（commons-dbutils-1.4）

@Test//原来不使用dbUtils工具的数据库查询代码实现
    public void jdbcQuery() throws Exception{
		List<Stud> studs = new ArrayList<Stud>();
    	Connection con = C3p0Pool.getConnection();
    	String sql = "select * from stud ";
    	Statement st = con.createStatement();
    	ResultSet  rs = st.executeQuery(sql);
    	while(rs.next()){
    		Stud s = new Stud();
    		s.setId(rs.getString("id"));
    		s.setName(rs.getString("name"));
    		studs.add(s);
    	}
    	System.out.println(studs);
    }
	
	@Test//使用dbUtils工具的数据库查询代码实现
	public void dbUtilsQuery() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		String sql = "select * from stud ";
		List<Stud> studs = run.query(sql,new BeanListHandler<Stud>(Stud.class) );
		System.out.println(studs);
	}
	@Test
	public void dbUtilsQuery2() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		String sql = "select * from stud ";
		List<Map<String, Object>> studs = run.query(sql, new MapListHandler() );
		System.out.println(studs);
	}
	
	////DbUtils工具的使用演示: 增删改--用update(),  查--用query()方法
	/*
	 CREATE TABLE person(
        id VARCHAR(30) PRIMARY KEY,
        NAME VARCHAR(30),
        address VARCHAR(30),
        age INT
     );
	 */
	@Test
	public void save() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		//statement方式
		//run.update("insert into person(id,name,address,age) values('A001','Jack','湖南长沙',22) ");
		//prepareStatement方式
		run.update("insert into person(id,name,address,age) values(?,?,?,?)","A003","Tom","中国西安",24);//如果参数个数或类型 与 “?”号不匹配，会出异常 
	}
	@Test
	public void saveTx() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		Connection con = C3p0Pool.getConnection();
		try{
			con.setAutoCommit(false);
			//※注意，实现事务功能时，要传入con对象，且多条语句共处一个事务时，要传入同一个con对象。但如果不实现事务功能，可以有传入con对象
			run.update(con,"insert into person(id,name,address,age) values(?,?,?,?)","A003","Tom","浙江杭州",24);
			run.update(con,"insert into person(id,name,address,age) values(?,?,?,?)","A003","Rose","江苏苏州",22);
			con.commit();			
		}catch (Exception e) {
			con.rollback();
			System.out.println("事务回滚了....");
		}finally{
			con.setAutoCommit(true);
			con.close();
		}
	}
	
	//下面演示一下查询的结果集封装功能
	@Test//封装成BeanList
	public void query1() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		//封装成BeanList: 如果值对象中的属性名和表中的字段名不一致，那么该属性的值返回的是null----解决:采用别名
		//List<Person> persons = run.query("select * from person ",new BeanListHandler<Person>(Person.class) );//没有采用别名，addr属性为null
		List<Person> persons = run.query("select id,name,address addr,age from person ",new BeanListHandler<Person>(Person.class) );//用属性名 当  字段别名
		System.out.println(persons);
	}
	
	@Test//封装成MapList
	public void query2() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		List<Map<String, Object>> persons = run.query("select * from person ",new MapListHandler() );
		System.out.println(persons);
	}
	
	@Test//封装成BeanList---查询带参数
	public void query3() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		String sql = "select id,name,address addr,age from person where name like ? and age>? ";
		List<Person> persons = run.query(sql,new BeanListHandler<Person>(Person.class),"%a%",25 );
		System.out.println(persons);
	}
	
	
	@Test//演示批处理功能
	public void batch() throws Exception{
		QueryRunner run = new QueryRunner(C3p0Pool.getDataSource());
		for(int i=1;i<=100;i++){
			String sql = "insert into stud(id,name) values(?,?) ";
			String str= "000"+i;
			str = str.substring(str.length()-3, str.length());
			String id1 = "A"+ str;
			String id2 = "B"+ str;
			//System.out.println(str);
			String params[][] = {{id1,"Alice"+i},{id2,"Bob"+i} };
			run.batch(sql, params);
		}
	}

ext增强操作，去除sql语句操作数据库：

////////以下演示扩展包commons-dbutilss-ext.jar的功能//////////////
	//注意，下面的用法要生效，必须给值对象添加注解
	@Test//封装成BeanList---直接通过JavaBean的字节码查询
	public void query4() throws Exception{
		ExtQueryRunner run = new ExtQueryRunner(C3p0Pool.getDataSource());
		List<Person> persons = run.query(Person.class);//不用sql语句，，直接查询Bean-List
		System.out.println(persons);
	}
	
	@Test//封装成BeanList---直接通过JavaBean的字节码查询
	public void save3() throws Exception{
		ExtQueryRunner run = new ExtQueryRunner(C3p0Pool.getDataSource());
		Stud stud = new Stud();
		stud.setId("A006");
		stud.setName("Alice");
		run.save(stud);//不用sql语句，，直接存对象
		
		System.out.println(stud);
	}

注意：使用ext,值对象要加注解

@Table(value="person")
public class Person {
	private String id;
	private String name;
	@Column(value="address")//该注解无效，反正以后开发时属性名都取成和表字段名一样
	private String addr;
	private Integer age;

	public String getId() {
		return id;
	}

	public void setId(String id) {//可以使得函数名与子段名一致获取
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getAddr() {
		return addr;
	}

	public void setAddr(String addr) {
		this.addr = addr;
	}

	public Integer getAge() {
		return age;
	}

	public void setAge(Integer age) {
		this.age = age;
	}

updata delete 函数要加入id注解：

@Id
	private double salay;
	@Column
	private int age;
	
	@Column
	private String name;
	@Column
	private String id;
	@Column
	private String sex;

sql语句为：update column注解 from table注解 where id注解

dbutils操作数据库