Question

如何把java对象存入数据库

Answer 1

　　假设有这么个对象：
import java.io.Serializable;

public class MyObject implements Serializable {

private static final long serialVersionUID = 1L;
private int i;

public int getI() {
return i;
}

public void setI(int i) {
this.i = i;
}
}

//测试 的方法如下
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;

public class test {

public static void main(String[] args) throws IOException,
ClassNotFoundException {

MyObject obj = new MyObject();
obj.setI(4567);
write(Object2Bytes(obj));

// read();
}

public static void write(byte[] b) throws ClassNotFoundException {

System.out.println(b.length);
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
try {
Connection con = DriverManager.getConnection("jdbc:odbc:temp");
String sql = "insert into tab values(?)";

PreparedStatement pstmt = con.prepareStatement(sql);
pstmt.setBytes(1, b);
pstmt.execute();

pstmt.close();
con.close();
} catch (Exception e) {
e.printStackTrace();
}
}

public static void read() throws ClassNotFoundException {
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
try {
Connection con = DriverManager.getConnection("jdbc:odbc:temp");
String sql = "select * from tab";

PreparedStatement pstmt = con.prepareStatement(sql);
ResultSet res = pstmt.executeQuery();

while (res != null && res.next()) {
byte[] b = res.getBytes("key");
System.out.println(b.length);
MyObject obj = (MyObject) Bytes2Object(b);
System.out.println(obj.getI());
}

pstmt.close();
con.close();
} catch (Exception e) {
e.printStackTrace();
}
}

// 将对象转换成字节数组
public static byte[] Object2Bytes(Object obj) throws IOException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(obj);
return baos.toByteArray();
}

// 将字节数组转换成为对象
public static Object Bytes2Object(byte[] b) throws IOException,
ClassNotFoundException {

ByteArrayInputStream bais = new ByteArrayInputStream(b);
ObjectInputStream ois = new ObjectInputStream(bais);

Object obj = ois.readObject();
return obj;
}

}

Answer 2

使用 java.sql.Clob或 Blob 写 入。。。。。。。。。对象先做序列化、转成byte[]或流。。。。