報文 組包 解包
- 在實際項目中經(jīng)常會碰到不同系統(tǒng)之間的數(shù)據(jù)交換祥楣，有些是用webservice订雾。有些則是使用發(fā)socket消息的方式慈省，將需要發(fā)送的消息組裝成特定格式的字符串或Xml格式的文件憔维，再通過socket編程發(fā)送到對方系統(tǒng)炬守。本文主要討論組裝成定長字符串牧嫉。
- 抽象任何一個定長消息包(MsgPackage)都是由一個或多個消息片(MsgPiece)組成。任何一個消息片都是由一個或多個消息域(MsgField)組成减途。消息域的屬性有：域名酣藻、長度、值鳍置、如果值的長度小于定義的最大長度那值是靠左還是右對齊其余的是用什么字符填充辽剧。
工具代碼
消息域類
package socket.msg;
/**
* 消息域
* @author Zhenwei.Zhang (2013-9-25)
*/
public class MsgField {
public MsgField (String name, int length, char fillChar, FillSide fillSide) {
this.name = name;
this.length = length;
this.fillChar = fillChar;
this.fillSide = fillSide;
}
/**
* 填充位置
* @author Zhenwei.Zhang (2013-9-25)
*/
public enum FillSide {
LEFT, RIGHT
}
/** 域名稱 */
private String name;
/** 長度 */
private int length;
/** 填充字符 */
private char fillChar;
/** 填充位置 */
private FillSide fillSide;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getLength() {
return length;
}
public void setLength(int length) {
this.length = length;
}
public char getFillChar() {
return fillChar;
}
public void setFillChar(char fillChar) {
this.fillChar = fillChar;
}
public FillSide getFillSide() {
return fillSide;
}
public void setFillSide(FillSide fillSide) {
this.fillSide = fillSide;
}
}
報文消息片類
package socket.msg;
import java.beans.PropertyDescriptor;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.Method;
import java.util.LinkedList;
import java.util.List;
import socket.msg.MsgField.FillSide;
/**
* 消息片，由多個消息域按一定的順序組成
* @author Zhenwei.Zhang (2013-9-25)
*/
public abstract class MsgPiece {
/** 消息域列表 */
private List<MsgField> itemList = new LinkedList<MsgField>();
public MsgPiece(MsgField[] items) {
itemList = new LinkedList<MsgField>();
for (int i = 0; i < items.length; i++) {
itemList.add(items[i]);
}
}
/**
* 組消息
* @author Zhenwei.Zhang (2013-9-25)
* @param charsetName
* @return
* @throws Exception
*/
public byte[] pack(String charsetName) throws Exception {
StringBuffer result = new StringBuffer();
byte[] b = null;
try {
for (MsgField item : itemList) {
PropertyDescriptor pd = new PropertyDescriptor(item.getName(), this.getClass());
Method readMethod = pd.getReadMethod();
Object gotVal = readMethod.invoke(this);
String strFill = gotVal == null ? "" : gotVal.toString();
result.append(this.autoFill(strFill, item.getFillChar(), item.getFillSide(), item.getLength(), charsetName));
}
b = result.toString().getBytes(charsetName);
} catch (Exception e) {
throw new Exception("組消息出錯：" + e.getMessage(), e);
}
return b;
}
/**
* 解消息
* @author Zhenwei.Zhang (2013-9-25)
* @param msg
* @param charsetName
* @throws Exception
*/
public void unPack(byte[] msg, String charsetName) throws Exception {
if (msg.length != this.getLength()) {
throw new Exception("解消息出錯税产，消息長度不合法怕轿！");
}
int index = 0;
try {
for (MsgField item : itemList) {
String value = new String(msg, index, item.getLength(), charsetName);
value = this.getRealVal(value, item.getFillSide(), item.getFillChar());
PropertyDescriptor pd = new PropertyDescriptor(item.getName(), this.getClass());
Method setMethod = pd.getWriteMethod();
if (pd.getPropertyType().equals(byte.class) || pd.getPropertyType().equals(Byte.class)) {
setMethod.invoke(this, Byte.parseByte(value));
}else if (pd.getPropertyType().equals(short.class) || pd.getPropertyType().equals(Short.class)) {
setMethod.invoke(this, Short.parseShort(value));
}else if (pd.getPropertyType().equals(int.class) || pd.getPropertyType().equals(Integer.class)) {
setMethod.invoke(this, Integer.parseInt(value));
}else if (pd.getPropertyType().equals(long.class) || pd.getPropertyType().equals(Long.class)) {
setMethod.invoke(this, Long.parseLong(value));
}else if (pd.getPropertyType().equals(float.class) || pd.getPropertyType().equals(Float.class)) {
setMethod.invoke(this, Float.parseFloat(value));
}else if (pd.getPropertyType().equals(double.class) || pd.getPropertyType().equals(Double.class)) {
setMethod.invoke(this, Double.parseDouble(value));
}else if (pd.getPropertyType().equals(char.class) || pd.getPropertyType().equals(Character.class)) {
setMethod.invoke(this, value.toCharArray()[0]);
}else if (pd.getPropertyType().equals(boolean.class) || pd.getPropertyType().equals(Boolean.class)) {
setMethod.invoke(this, Boolean.valueOf(value));
}else {
setMethod.invoke(this, value);
}
index += item.getLength();
}
} catch (Exception e) {
throw new Exception("解消息出錯：" + e.getMessage(), e);
}
}
/**
* 獲得消息片長
* @author Zhenwei.Zhang (2013-9-25)
* @return
*/
public int getLength() {
int length = 0;
for (MsgField item : itemList) {
length += item.getLength();
}
return length;
}
/**
* 格式化真實值為指定長度字符串，超長自動截取
* @author Zhenwei.Zhang (2013-9-26)
* @param value
* @param fillChar 填充字符
* @param side 填充位置
* @param totalLen 域定義的長度
* @param charsetName 編碼
* @return
*/
private String autoFill(String value, char fillChar, FillSide side, int totalLen, String charsetName) {
try {
if (value == null) {
value = "";
}
StringBuffer sbuffBuffer = new StringBuffer();
// 長度超過指定長度辟拷，截取
if (value.getBytes(charsetName).length > totalLen) {
byte[] data = new byte[totalLen];
System.arraycopy(value.getBytes(charsetName), 0, data, 0, totalLen);
sbuffBuffer.append(new String(data, charsetName));
return sbuffBuffer.toString();
}
if (side == socket.msg.MsgField.FillSide.RIGHT) {
sbuffBuffer.append(value);
}
for (int i = value.getBytes(charsetName).length; i < totalLen; i++) {
sbuffBuffer.append(fillChar);
}
if (side == socket.msg.MsgField.FillSide.LEFT) {
sbuffBuffer.append(value);
}
return sbuffBuffer.toString();
} catch (UnsupportedEncodingException e) {
throw new RuntimeException("系統(tǒng)不支持" + charsetName + "編碼");
}
}
/**
* 獲得消息域的真實值
* @author Zhenwei.Zhang (2013-9-26)
* @param value
* @param side 填充位置
* @param fillChar 填充字符
* @return
* @throws Exception
*/
private String getRealVal(String value, FillSide side, char fillChar) throws Exception {
char[] chars = value.toCharArray();
if (FillSide.LEFT == side) {
int index = 0;
for (int i = 0; i < chars.length; i++) {
if (fillChar == chars[i]) {
index ++;
} else {
continue;
}
}
return value.substring(index);
} else if (FillSide.RIGHT == side) {
int index = chars.length - 1;
for (int i = index; i >= 0; i--) {
if (fillChar == chars[i]) {
index --;
} else {
continue;
}
}
return value.substring(0, index + 1);
} else {
throw new Exception("無效的填充位置");
}
}
}
消息包類
package socket.msg;
import java.beans.PropertyDescriptor;
import java.lang.reflect.Method;
/**
* 消息包撞羽，由多個消息片組成
* @author Zhenwei.Zhang (2013-10-12)
*/
public abstract class MsgPackage {
/** 消息包的消息片數(shù)組 */
String[] pieces = null;
public MsgPackage(String... pieName) {
pieces = pieName;
}
/**
* 組包
* @author Zhenwei.Zhang (2013-9-26)
* @param charsetName
* @return
* @throws Exception
*/
public byte[] pack(String charsetName) throws Exception {
int index = 0;
byte[] result = new byte[this.getLength()];
for (String p : pieces) {
PropertyDescriptor pd = new PropertyDescriptor(p, this.getClass());
Method getterMethod = pd.getReadMethod();
MsgPiece piece = (MsgPiece)getterMethod.invoke(this);
if (piece == null) { //屬性為空則該屬性組空串
piece = (MsgPiece) pd.getPropertyType().newInstance();
}
byte[] t = piece.pack(charsetName);
System.arraycopy(t, 0, result, index, t.length);
index += t.length;
}
return result;
}
/**
* 解包
* @author Zhenwei.Zhang (2013-9-26)
* @param msg
* @param charsetName
* @throws Exception
*/
public void unPack(byte[] msg, String charsetName) throws Exception {
if (msg.length != this.getLength()) {
throw new Exception("解消息出錯，消息包長度不合法衫冻！");
}
int index = 0;
for (String p : pieces) { // 創(chuàng)建一個新的屬性對象诀紊，解包，賦值
PropertyDescriptor pd = new PropertyDescriptor(p, this.getClass());
Method writeMethod = pd.getWriteMethod();
MsgPiece piece = (MsgPiece) pd.getPropertyType().newInstance();
byte[] t = new byte[piece.getLength()];
System.arraycopy(msg, index, t, 0, t.length);
piece.unPack(t, charsetName);
writeMethod.invoke(this, piece);
index += t.length;
}
}
/**
* 獲得消息包長度
* @author Zhenwei.Zhang (2013-9-26)
* @return
* @throws Exception
*/
public int getLength() throws Exception {
int length = 0;
try {
for (String p : pieces) {
PropertyDescriptor pd = new PropertyDescriptor(p, this.getClass());
Method getterMethod = pd.getReadMethod();
MsgPiece piece = (MsgPiece)getterMethod.invoke(this);
if (piece == null) {
piece = (MsgPiece) pd.getPropertyType().newInstance();
}
length += piece.getLength();
}
} catch (Exception e) {
throw new Exception("獲得消息包長度錯誤：" + e.getMessage(), e);
}
return length;
}
}
實例
以下是使用上述封裝做的簡單實現(xiàn)例子：
定義一個消息由消息頭和消息體組成隅俘，消息頭由name,sex,UAge,amt等屬性組成邻奠，消息體由content屬性組成到推。
package socket.msg.test;
import socket.msg.MsgField;
import socket.msg.MsgPiece;
import socket.msg.MsgField.FillSide;
public class TestHead extends MsgPiece {
private String name;
private boolean sex;
private int UAge;
private String URL;
private double amt;
public int getUAge() {
return UAge;
}
public void setUAge(int uAge) {
UAge = uAge;
}
public double getAmt() {
return amt;
}
public void setAmt(double amt) {
this.amt = amt;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isSex() {
return sex;
}
public void setSex(boolean sex) {
this.sex = sex;
}
public String getURL() {
return URL;
}
public void setURL(String uRL) {
URL = uRL;
}
private static final MsgField[] items = new MsgField[]{
new MsgField("name", 10, ' ', FillSide.RIGHT),
new MsgField("sex", 10, '0', FillSide.LEFT),
new MsgField("UAge", 10, '0', FillSide.LEFT),
new MsgField("URL", 10, ' ', FillSide.RIGHT),
new MsgField("amt", 10, '0', FillSide.LEFT)
};
public TestHead() {
super(items);
}
}
package socket.msg.test;
import socket.msg.MsgField;
import socket.msg.MsgPiece;
import socket.msg.MsgField.FillSide;
public class TestBody extends MsgPiece {
private static final MsgField[] items = new MsgField[]{
new MsgField("content", 20, ' ',FillSide.RIGHT),
};
public TestBody() {
super(items);
}
private String content;
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
}
package socket.msg.test;
import socket.msg.MsgPackage;
public class TestPackage extends MsgPackage {
public TestPackage() {
super("t1", "t2");
}
private TestHead t1;
private TestBody t2;
public TestHead getT1() {
return t1;
}
public void setT1(TestHead t1) {
this.t1 = t1;
}
public TestBody getT2() {
return t2;
}
public void setT2(TestBody t2) {
this.t2 = t2;
}
}
測試
package socket.msg.test;
import java.io.UnsupportedEncodingException;
public class Test {
/**
* @author Zhenwei.Zhang (2013-11-12)
* @param args
* @throws Exception
* @throws UnsupportedEncodingException
*/
public static void main(String[] args) throws UnsupportedEncodingException, Exception {
TestHead head = new TestHead();
head.setName("name");
head.setAmt(12.121);
head.setSex(false);
head.setURL("http://asdsaaaaaaaaaaaaaaaaaaaaaaa");
head.setUAge(111);
TestBody body = new TestBody();
body.setContent("content");
TestPackage packagee = new TestPackage();
packagee.setT1(head);
packagee.setT2(body);
System.out.println(new String(packagee.pack("GBK"), "GBK"));
TestPackage packagee2 = new TestPackage();
String str = "name 000000true0000000111http://asd000012.121content ";
packagee2.unPack(str.getBytes("GBK"), "GBK");
System.out.println(packagee2.getT1().isSex());
}
}
