JDBC中大文本类型处理

- 日理万妓 2022-06-08 01:21 182阅读 0赞

clob(test) blob

public class App_text {
    	// 全局参数
    	private Connection con;
    	private Statement stmt;
    	private PreparedStatement pstmt;
    	private ResultSet rs;
     
    	@Test
    	// 1. 保存大文本数据类型   ( 写longtext)
    	public void testSaveText() {
    		String sql = "insert into test(content) values(?)";
    		try {
    			// 连接
    			con = JdbcUtil.getConnection();
    			// pstmt 对象
    			pstmt = con.prepareStatement(sql);
    			// 设置参数
    			// 先获取文件路径
    			String path = App_text.class.getResource("tips.txt").getPath();
    			FileReader reader = new FileReader(new File(path));
    			pstmt.setCharacterStream(1, reader);
    			// 执行sql
    			pstmt.executeUpdate();
    			// 关闭
    			reader.close();
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			JdbcUtil.closeAll(con, pstmt, null);
    		}
    	}
    	@Test
    	// 2. 读取大文本数据类型   ( 读longtext)
    	public void testGetAsText() {
    		String sql = "select * from  test;";
    		try {
    			// 连接
    			con = JdbcUtil.getConnection();
    			// pstmt 对象
    			pstmt = con.prepareStatement(sql);
    			// 读取
    			rs = pstmt.executeQuery();
    			if (rs.next()) {
    				// 获取长文本数据, 方式1:
    				//Reader r = rs.getCharacterStream("content");
    				// 获取长文本数据, 方式2:
    				System.out.print(rs.getString("content"));
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			JdbcUtil.closeAll(con, pstmt, null);
    		}
    	}
    }

public class App_blob {
    	// 全局参数
    	private Connection con;
    	private Statement stmt;
    	private PreparedStatement pstmt;
    	private ResultSet rs;
     
    	@Test
    	// 1. 二进制数据类型   ( 写longblob)
    	public void testSaveText() {
    		String sql = "insert into test(img) values(?)";
    		try {
    			// 连接
    			con = JdbcUtil.getConnection();
    			// pstmt 对象
    			pstmt = con.prepareStatement(sql);
    			// 获取图片流
    			InputStream in = App_text.class.getResourceAsStream("7.jpg");
    			pstmt.setBinaryStream(1, in);
    			// 执行保存图片
    			pstmt.execute();
    			// 关闭
    			in.close();
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			JdbcUtil.closeAll(con, pstmt, null);
    		}
    	}
    	@Test
    	// 2. 读取大文本数据类型   ( 读longblob)
    	public void testGetAsText() {
    		String sql = "select img from  test where id=2;";
    		try {
    			// 连接
    			con = JdbcUtil.getConnection();
    			// pstmt 对象
    			pstmt = con.prepareStatement(sql);
    			// 读取
    			rs = pstmt.executeQuery();
    			if (rs.next()) {
    				// 获取图片流
    				InputStream in = rs.getBinaryStream("img");
    				// 图片输出流
    				FileOutputStream out = new FileOutputStream(new File("c://1.jpg"));
    				int len = -1;
    				byte b[] = new byte[1024];
    				while ((len = in.read(b)) != -1) {
    					out.write(b, 0, len);
    				}
    				// 关闭
    				out.close();
    				in.close();
    			}
    		} catch (Exception e) {
    			e.printStackTrace();
    		} finally {
    			JdbcUtil.closeAll(con, pstmt, null);
    		}
    	}
    }