ByteArrayOutputStream類是在創建它的實例時,程序內部創建一個byte型別數組的緩衝區,然後利用ByteArrayOutputStream和ByteArrayInputStream的實例向數組中寫入或讀出byte型數據。在網絡傳輸中我們往往要傳輸很多變量,我們可以利用ByteArrayOutputStream把所有的變量收集到一起,然後一次性把數據發送出去。具體用法如下:
ByteArrayOutputStream:
ByteArrayInputStream: 可以將字節數組轉化爲輸入流
1import java.io.*;
2
3public class test {
4 public static void main(String[] args) {
5 int a=0;
6 int b=1;
7 int c=2;
8 ByteArrayOutputStream bout = new ByteArrayOutputStream();
9 bout.write(a);
10 bout.write(b);
11 bout.write(c);
12 byte[] buff = bout.toByteArray();
13 for(int i=0; i<buff.length; i++)
14 System.out.println(buff[i]);
15 System.out.println("***********************");
16 ByteArrayInputStream bin = new ByteArrayInputStream(buff);
17 while((b=bin.read())!=-1) {
18 System.out.println(b);
19 }
20 }
21}
22
23
24
2
3public class test {
4 public static void main(String[] args) {
5 int a=0;
6 int b=1;
7 int c=2;
8 ByteArrayOutputStream bout = new ByteArrayOutputStream();
9 bout.write(a);
10 bout.write(b);
11 bout.write(c);
12 byte[] buff = bout.toByteArray();
13 for(int i=0; i<buff.length; i++)
14 System.out.println(buff[i]);
15 System.out.println("***********************");
16 ByteArrayInputStream bin = new ByteArrayInputStream(buff);
17 while((b=bin.read())!=-1) {
18 System.out.println(b);
19 }
20 }
21}
22
23
24
如上所示,ByteArrayOutputStream把內存中的數據讀到字節數組中,而ByteArrayInputStream又把字節數組中的字節以流的形式讀出,實現了對同一個字節數組的操作.
綜合DataOutputStream&DataInputStream的作用和功能,與ByteArrayOutputStream和ByteArrayInputSream使用將更方便.此時DataOutputStream&DataInputStream封閉了字節流,以適當的形式讀出了字節數組中的數據.如下所示:
1import java.io.*;
2
3public class test {
4 public static void main(String[] args)throws IOException {
5 ByteArrayOutputStream bout = new ByteArrayOutputStream();
6 DataOutputStream dout = new DataOutputStream(bout);
7 String name = "xxy";
8 int age = 84;
9 dout.writeUTF(name);
10 dout.writeInt(age);
11 byte[] buff = bout.toByteArray();
12 ByteArrayInputStream bin = new ByteArrayInputStream(buff);
13 DataInputStream dis = new DataInputStream(bin);
14 String newName = dis.readUTF();
15 int newAge = dis.readInt();
16 System.out.println(newName+":"+newAge);
17 }
18}
2
3public class test {
4 public static void main(String[] args)throws IOException {
5 ByteArrayOutputStream bout = new ByteArrayOutputStream();
6 DataOutputStream dout = new DataOutputStream(bout);
7 String name = "xxy";
8 int age = 84;
9 dout.writeUTF(name);
10 dout.writeInt(age);
11 byte[] buff = bout.toByteArray();
12 ByteArrayInputStream bin = new ByteArrayInputStream(buff);
13 DataInputStream dis = new DataInputStream(bin);
14 String newName = dis.readUTF();
15 int newAge = dis.readInt();
16 System.out.println(newName+":"+newAge);
17 }
18}