第十七天dbutils的使用------CommonsDbUtils(Apache)第三方的:只是对JDBC编码进行了简单的封装 - 数据库编程

ccount where id= ", new BeanHandler(Account.class),1); System.out.println(a); } @Test public void testFindAll() throws Exception{ List list = qr.query("select * from account", new BeanListHandler(Account.class)); for(Account a:list) System.out.println(a); } //插入大文本行不行：知道clob对应的类型是什么 /* * create table t1(id int,content text); */ @Test public void testText() throws Exception{ File file = new File("src/jpm.txt"); Reader reader = new FileReader(file);//流并没有对应的数据库类型 char ch[] = new char[(int)file.length()]; reader.read(ch);//不好，开发中不用 reader.close(); Clob clob = new SerialClob(ch); qr.update("insert into t1(id,content) values( , )", 1,clob); } //插入大二进制行不行：知道blob对应的类型是什么 /* * create table t2(id int,content longblob); */ @Test public void testBlob() throws Exception{ InputStream in = new FileInputStream("src/1.jpg"); byte b[] = new byte[in.available()]; in.read(b); in.close(); Blob blob = new SerialBlob(b); qr.update("insert into t2(id,content) values( , )", 1,blob); } //批处理 /* * create table t3(id int,name varchar(200)); */ @Test public void testBatch()throws Exception{ Object params[][] = new Object[10][];//第1维，插入的条数。第2维，每条需要的参数 for(int i=0;i

部分源代码如下：说明已经关闭资源了。

  public int update(String sql, Object... params) throws SQLException {
        Connection conn = this.prepareConnection();

        return this.update(conn, true, sql, params);
    }

    /**
     * Calls update after checking the parameters to ensure nothing is null.
     * @param conn The connection to use for the update call.
     * @param closeConn True if the connection should be closed, false otherwise.
     * @param sql The SQL statement to execute.
     * @param params An array of update replacement parameters.  Each row in
     * this array is one set of update replacement values.
     * @return The number of rows updated.
     * @throws SQLException If there are database or parameter errors.
     */
    private int update(Connection conn, boolean closeConn, String sql, Object... params) throws SQLException {
        if (conn == null) {
            throw new SQLException("Null connection");
        }

        if (sql == null) {
            if (closeConn) {
                close(conn);
            }
            throw new SQLException("Null SQL statement");
        }

        PreparedStatement stmt = null;
        int rows = 0;

        try {
            stmt = this.prepareStatement(conn, sql);
            this.fillStatement(stmt, params);
            rows = stmt.executeUpdate();

        } catch (SQLException e) {
            this.rethrow(e, sql, params);

        } finally {
            close(stmt);
            if (closeConn) {
                close(conn);
            }
        }

        return rows;
    }

}

DBUtils框架提供的结果处理器例子:

public class ResultSetHandlerDemo {
	private QueryRunner qr = new QueryRunner(DBCPUtil.getDataSource());
	
	//ArrayHandler：把结果集中的第一行数据转成对象数组。
	@Test
	public void test1() throws SQLException{
		//数组中的元素就是记录的每列的值
		Object[] objs = qr.query("select * from account where id= ", new ArrayHandler(), 1);
		for(Object obj:objs)
			System.out.println(obj);
	}
	//ArrayListHandler：把结果集中的每一行数据都转成一个数组，再存放到List中。
	@Test
	public void test2() throws SQLException{
		//数组中的元素就是记录的每列的值
		List list = qr.query("select * from account", new ArrayListHandler());
		for(Object[] objs:list){
			System.out.println("------------------");
			for(Object obj:objs){
				System.out.println(obj)

第十七天dbutils的使用------CommonsDbUtils(Apache)第三方的:只是对JDBC编码进行了简单的封装(二)