本文主要是介绍JAVA---BLOB数据的插入与查询,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!
package java5.blob;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.Date;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import org.junit.Test;
import java3.bean.Customer;
import java3.util.JDBCUtils;
/*
* 使用preparedStatement操作Blob类型的数据
*/
public class BlobTest {
//向数据表customers中插入Blob类型的字段
@Test
public void testInsert() throws Exception{
Connection conn = JDBCUtils.getConnedtion();
String sql="insert into customers(name,email,birth,photo)values(?,?,?,?)";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setObject(1, "lion");
ps.setObject(2, "1123123@163.com");
ps.setObject(3, "1111-2-3");
FileInputStream is = new FileInputStream(new File("2.png"));
ps.setBlob(4, is);
ps.execute();
JDBCUtils.closeResource(conn, ps);
}
//查询数据表customers中Blob类型的字段
@Test
public void testQuery() {
InputStream is=null;
FileOutputStream fos=null;
Connection conn =null;
PreparedStatement ps=null;
ResultSet rs =null;
try {
conn = JDBCUtils.getConnedtion();
String sql="select id,name,email,birth,photo from customers where id=?";
ps = conn.prepareStatement(sql);
ps.setObject(1, 21);
rs = ps.executeQuery();
if(rs.next()){
int id=rs.getInt("id");
String name = rs.getString("name");
String email = rs.getString("email");
Date birth = rs.getDate("birth");
Customer customer = new Customer(id, name, email, birth);
System.out.println(customer);
//将blob类型的字段下载下来,以文件的方式保存在本地
Blob photo = rs.getBlob("photo");
is = photo.getBinaryStream();
fos = new FileOutputStream("3.png");
byte[] buffer=new byte[1024];
int len;
while((len=is.read(buffer))!=-1){
fos.write(buffer, 0, len);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally{
if(is!=null){
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(fos!=null){
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
JDBCUtils.closeResource(conn, ps, rs);
}
}
}
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