插入与读取Blob类型数据

时间:2023-03-10 04:20:49
插入与读取Blob类型数据

BlobTest

package com.aff.PreparedStatement;
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 org.junit.Test;
import com.aff.bean.Customer;
import com.aff.utils.JDBCUtils; //向数据表Customers插入Blob类型的字段
public class BlobTest { // 向数据表customers插入Blob类型的字段
@Test
public void testInsert() throws Exception {
Connection conn = JDBCUtils.getConnection();
String sql = " insert into customers(name,email,birth,photo)values(?,?,?,?)";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setObject(1, "何苗苗");
ps.setObject(2, "hemiao@163.com");
ps.setObject(3, "1996-2-3");
FileInputStream is = new FileInputStream(new File("1.jpg"));
ps.setObject(4, is);
ps.execute();
JDBCUtils.closeResource(conn, ps);
} //查询数据表customers中的Blob类型字段
@Test
public void testQuery() {
Connection conn = null;
PreparedStatement ps = null;
InputStream is = null;
FileOutputStream fos = null;
ResultSet rs = null;
try {
conn = JDBCUtils.getConnection();
String sql = "select id,name,email,birth,photo from customers where id = ?";
ps = conn.prepareStatement(sql);
ps.setInt(1, 20);
rs = ps.executeQuery();
if (rs.next()) {
// 方式一
// int id = rs.getInt(1);
// String name = rs.getString(2);
// String email = rs.getString(3);
// Date birth = rs.getDate(4);
// 方式二
int id = rs.getInt("id");
String name = rs.getString("name");
String email = rs.getString("email");
Date birth = rs.getDate("birth"); Customer cust = new Customer(id, name, email, birth);
System.out.println(cust); // 将Blob的字段下载下来,以文件的方式保存到本地
Blob photo = rs.getBlob("photo");
is = photo.getBinaryStream();
fos = new FileOutputStream(new File("mm.jpg"));
byte[] buffer = new byte[1024];
int len;
while ((len = is.read(buffer)) != -1) {
fos.write(buffer, 0, len);
}
}
} catch (Exception e) {
e.printStackTrace();
} finally { try {
if(is != null)
is.close();
} catch (IOException e) {
e.printStackTrace();
}
try {
if(fos !=null)
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
JDBCUtils.closeResource(conn, ps, rs);
}
}
}

文件位置

插入与读取Blob类型数据