关于数据库保存流java流对象
如何实现数据库保存一个java的流对象,需要什么步骤请高手指点指点是web方向的通过接受一个流对象然后保存到数据库的BLOB类型中不知道该怎么写...
如何实现数据库保存一个java的流对象,需要什么步骤 请高手指点指点
是web方向的 通过接受一个流对象 然后保存到数据库的BLOB类型中 不知道该怎么写 展开
是web方向的 通过接受一个流对象 然后保存到数据库的BLOB类型中 不知道该怎么写 展开
展开全部
什么》? 哎呀没必要。。
不过可实现的:如下为一个通用的例子:
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;
}
}
不过可实现的:如下为一个通用的例子:
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;
}
}
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