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J2ME隨筆,記錄成長的腳步

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[JAVA]Utils類,java數據類型轉換小結

2010年來了，為迎接虎年大吉，記住這個不平凡的虎年，今天開始寫東西！
時至今日，J2ME方面的東西也有了一定的積累，好久不整理，有些東西都慢慢的開始生疏了，為了紀念曾經那些個日日夜夜的努力，在J2ME領域的不懈探索，本人決定，把當前所掌握的東東，分類整理出來，以此為曾經拼搏的我表示敬意！

開始今天的內容，整理了部分Java數據類型的轉換，拿過來直接可以使用：

import java.io.*;

import java.net.SocketTimeoutException;

/**

* User: duchangfeng

* Date: 2010-02-22

* Time: 15:12:30

*/

public class Utils {

public static String appendToBinaryString(int size, String s) {

if (s == null) s = "";

for (int i = s.length(); i < size; i++) {

s = new StringBuilder().append("0").append(s).toString();

}

return s;

}

/**

* 從InputStream中讀取一個Integer數據

*

* @param is

* @return

* @throws java.io.IOException

*/

public synchronized int readInt(InputStream is) throws IOException {

try {

byte[] _byte = new byte[4];

synchronized (_byte) {

// readLargeSize(is,_byte,0);

is.read(_byte);

ByteArrayInputStream buf = new ByteArrayInputStream(_byte);

DataInputStream in = new DataInputStream(buf);

int readed = in.readInt();

// System.out.println("read int "+readed);

if (readed > ConfigReader.getMaxPacketSize()) {

System.out.println(_byte);

}

return readed;

}

} catch (Exception e) {

// e.printStackTrace();

return (int) 0;

}

/**

* 從字節數組中讀取一個Integer數據

*

* @param bytes

* @return

* @throws java.io.IOException

*/

public synchronized int readInt(byte[] bytes) throws IOException {

try {

ByteArrayInputStream buf = new ByteArrayInputStream(bytes);

DataInputStream in = new DataInputStream(buf);

int readed = in.readInt();

// System.out.println("read int "+readed);

return readed;

} catch (Exception e) {

e.printStackTrace();

return (int) 0;

}

/**

* 從字節數組中讀取一個Short數據

*

* @param bytes

* @return

* @throws java.io.IOException

*/

public synchronized short readShort(byte[] bytes) throws IOException {

try {

ByteArrayInputStream buf = new ByteArrayInputStream(bytes);

DataInputStream in = new DataInputStream(buf);

short readed = in.readShort();

// System.out.println("read int "+readed);

return readed;

} catch (Exception e) {

e.printStackTrace();

return (int) 0;

}

/**

* 從字節數組中讀取一個Long數據

*

* @param bytes

* @return

* @throws java.io.IOException

*/

public synchronized long readLong(byte[] bytes) throws IOException {

try {

ByteArrayInputStream buf = new ByteArrayInputStream(bytes);

DataInputStream in = new DataInputStream(buf);

long readed = in.readLong();

// System.out.println("read int "+readed);

return readed;

} catch (Exception e) {

e.printStackTrace();

return (int) 0;

}

/**

* 獲取Integer的字節數組

*

* @param target

* @return

* @throws java.io.IOException

*/

public byte[] getBytes(int target) throws IOException {

ByteArrayOutputStream buf = new ByteArrayOutputStream();

DataOutputStream out = new DataOutputStream(buf);

out.writeInt(target);

return buf.toByteArray();

}

/**

* 從InputStream中讀取一個Short數據

*

* @param is

* @return

* @throws IOException

*/

public synchronized short readShort(InputStream is) throws IOException {

try {

byte[] _byte = new byte[2];

synchronized (_byte) {

// readLargeSize(is,_byte,0);

is.read(_byte);

ByteArrayInputStream buf = new ByteArrayInputStream(_byte);

DataInputStream in = new DataInputStream(buf);

short readed = in.readShort();

// System.out.println("read short "+readed);

return readed;

}

} catch (Exception e) {

return (short) 0;

}

/**

* 獲取Short的字節數組

*

* @param target

* @return

* @throws java.io.IOException

*/

public byte[] getBytes(short target) throws IOException {

ByteArrayOutputStream buf = new ByteArrayOutputStream();

DataOutputStream out = new DataOutputStream(buf);

out.writeShort(target);

return buf.toByteArray();

}

/**

* 從InputStream中讀取一個Long數據

*

* @param is

* @return

* @throws IOException

*/

public synchronized long readLong(InputStream is) throws IOException {

try {

byte[] _byte = new byte[8];

synchronized (_byte) {

is.read(_byte);

// readLargeSize(is,_byte,0);

ByteArrayInputStream buf = new ByteArrayInputStream(_byte);

DataInputStream in = new DataInputStream(buf);

long readed = in.readLong();

// System.out.println("read long "+readed);

return readed;

}

} catch (Exception e) {

return (long) 0;

}

/**

* 獲取Long的字節數組

*

* @param target

* @return

* @throws java.io.IOException

*/

public byte[] getBytes(long target) throws IOException {

ByteArrayOutputStream buf = new ByteArrayOutputStream();

DataOutputStream out = new DataOutputStream(buf);

out.writeLong(target);

return buf.toByteArray();

}

public synchronized void readLargeSize(InputStream is, byte[] filePieces, int nowoffset) throws IOException, InterruptedException {

int read = 0;

try {

read = is.read(filePieces, nowoffset, filePieces.length - nowoffset);

System.out.println("讀取了" + read + "個字節.");

if (read != filePieces.length - nowoffset) {

readLargeSize(is, filePieces, nowoffset + read);

}

} catch (SocketTimeoutException e) {

System.out.println("read time out,nowoffset is " + (nowoffset + read));

e.printStackTrace();

}

posted on 2010-02-22 15:38 騎豬闖天下閱讀(560) 評論(0) 編輯收藏

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[JAVA]Utils類,java數據類型轉換小結