第一步：创建表
DROP TABLE IF EXISTS `blob_test`; CREATE TABLE `blob_test` ( `id` int(11) NOT NULL AUTO_INCREMENT, `big_bit` blob COMMENT '二进制数据', PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8; 第二步：编写测试类中的代码 package cn.itcast.jdbc; import java.io.BufferedInputStream; import java.io.BufferedOutputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import org.junit.Test; public class BlobTest { /** * 测试向表中插入二进制数据 * @throws SQLException * @throws IOException */ @Test public void testCreate() throws SQLException, IOException { create(); } /** * 从表中查询二进制数据 * @throws SQLException * @throws IOException */ @Test public void testRead() throws SQLException, IOException { read(); } /** * 从数据库中查询结果 * @throws SQLException * @throws IOException */ static void read() throws SQLException, IOException { Connection conn = null; Statement st = null; ResultSet rs = null; try { //建立连接,JdbcUtils参考前一篇博客 conn = JdbcUtils.getConnection(); //创建语句 st = conn.createStatement(); //执行语句 rs = st.executeQuery("select big_bit from blob_test"); //处理结果 while(rs.next()) { //Blob blob = rs.getBlob(1); //InputStream in = blob.getBinaryStream(); InputStream in = rs.getBinaryStream("big_bit"); File file = new File("IMG_0002_bak.jpg"); OutputStream out = new BufferedOutputStream(new FileOutputStream(file)); byte[] buff = new byte[1024]; int i = 0; //从输入流读取对象 while((i = in.read(buff)) > 0) { out.write(buff, 0, i); } out.close(); in.close(); } } finally { JdbcUtils.free(rs, st, conn); } } /** * 向数据库中插入二进制数据 * @throws SQLException * @throws IOException */ static void create() throws SQLException, IOException { Connection conn = null; PreparedStatement ps = null; ResultSet rs = null; try{ conn = JdbcUtils.getConnection(); //创建语句 String sql = "insert into blob_test(big_bit) values(?)"; ps = conn.prepareStatement(sql); File file = new File("IMG_0002.jpg"); InputStream in = new BufferedInputStream(new FileInputStream(file)); ps.setBinaryStream(1, in, file.length()); //执行语句 int i = ps.executeUpdate(); in.close(); System.out.println("i=" + i); }finally{ JdbcUtils.free(rs, ps, conn); } } } ResultSet是不应该作为返回的，因为一旦Connection关闭，Statement和ResultSet中的数据全部都会变得无效。