重写java.util.Properties工具类 内容有序 不丢注释

package com.vrv.util; 


import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.Writer;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Properties;
import java.util.Set;


/** 
 *   CommentedProperties
 *   针对Properties进行扩展的工具类
 *   
 *   扩展的两个主要功能:
 *   1.对Properties文件中注释的保存。
 *       CommentedProperties在读取和保存Properties文件时,会将其注释
 *       一起读取保存。CommentedProperties中会提供方法来根据key获取
 *       相应注释。在CommentedProperties中添加一个K-V对时，也会提供
 *       添加相应注释的方法。
 *       
 *   2.对Properties文件中Key值顺序的保证。
 *       CommentedProperties会保证Key的顺序。从一个Properties文件中
 *       读取所有K-V对，保存到另一个Properties文件时，Key的顺序不会
 *       改变。
 *       
 *
 * @author BrokenDreams
 */
public class CommentedProperties{


/**
* 内部属性表
*/
private final Properties props;


/**
* 保存key与comment的映射，
* 同时利用这个映射来保证key的顺序。
*/
private final LinkedHashMap<String, String> keyCommentMap = new LinkedHashMap<String, String>();


private static final String BLANK = "";


public CommentedProperties() {
super();
props = new Properties();
}


public CommentedProperties(Properties defaults) {
super();
props = new Properties(defaults);
}


/**
* 设置一个属性，如果key已经存在，那么将其对应value值覆盖。
* @param key
* @param value
* @return
*/
public String setProperty(String key, String value) {
return setProperty(key, value, BLANK);
}


/**
* 设置一个属性，如果key已经存在，那么将其对应value值覆盖。
* 
* @param key 键
* @param value 与键对应的值
* @param comment 对键值对的说明
* @return
*/
public synchronized String setProperty(String key, String value, String comment){
Object oldValue = props.setProperty(key, value);
if(BLANK.equals(comment)){
if(!keyCommentMap.containsKey(key)){
keyCommentMap.put(key, comment);
}
}else{
keyCommentMap.put(key, comment);
}
return (String)oldValue;
}

/**
* 根据key获取属性表中相应的value。
* 
* @param key
* @return
*/
public String getProperty(String key) {
return props.getProperty(key);
}


/**
* 根据key获取属性表中相应的value。
* 如果没找到相应的value，返回defaultValue。
* 
* @param key
* @param defaultValue
* @return
*/
public String getProperty(String key, String defaultValue) {
return props.getProperty(key, defaultValue);
}


/**
* 从一个字符流中读取属性到属性表中
* 
* @param reader
* @throws IOException
*/
public synchronized void load(Reader reader) throws IOException {
load0(new LineReader(reader));
}


/**
* 从一个字节流中读取属性到属性表中
* 
* @param inStream
* @throws IOException
*/
public synchronized void load(InputStream inStream) throws IOException {
load0(new LineReader(inStream));
}


/**
* 从一个字节流中读取属性到属性表中
* 
* @param inStream
* @param charset
* @throws IOException
*/
public synchronized void load(InputStream inStream, String charset) throws IOException {
InputStreamReader reader = new InputStreamReader(inStream, charset);
load0(new LineReader(reader));
}


/**
* 从一个文件中读取属性到属性表中
* 
* @param file 属性文件
* @param charset 字符集
* @throws IOException
*/
public synchronized void load(File file, String charset) throws IOException {
FileInputStream inputStream = new FileInputStream(file);
InputStreamReader reader = new InputStreamReader(inputStream, charset);
load0(new LineReader(reader));
}


/**
* 从一个文件中读取属性到属性表中
* 默认字符集为utf-8
* 
* @param file 属性文件
* @throws IOException
*/
public synchronized void load(File file) throws IOException {
FileInputStream inputStream = new FileInputStream(file);
InputStreamReader reader = new InputStreamReader(inputStream, "utf-8");
load0(new LineReader(reader));
}

/**
* 将属性表中的属性写到字符流里面。
* 
* @param writer
* @throws IOException
*/
public void store(Writer writer) throws IOException {
store0((writer instanceof BufferedWriter)?(BufferedWriter)writer
: new BufferedWriter(writer),false);
}


/**
* 将属性表中的属性写到字节流里面。
* 
* @param out
* @throws IOException
*/
public void store(OutputStream out) throws IOException {
store0(new BufferedWriter(new OutputStreamWriter(out, "utf-8")),true);
}


/**
* 如果属性表中某个key对应的value值和参数value相同
* 那么返回true，否则返回false。
* 
* @param value
* @return
*/
public boolean containsValue(String value) {
return props.containsValue(value);
}


/**
* 如果属性表中存在参数key，返回true，否则返回false。
* 
* @param key
* @return
*/
public boolean containsKey(String key) {
return props.containsKey(key);
}

/**
* 获取属性表中键值对数量
* @return
*/
public int size() {
return props.size();
}


/**
* 检查属性表是否为空
* @return
*/
public boolean isEmpty() {
return props.isEmpty();
}


/**
* 清空属性表
*/
public synchronized void clear() {
props.clear();
keyCommentMap.clear();
}


/**
* 获取属性表中所有key的集合。
* 
* @return
*/
public Set<String> propertyNames() {
return props.stringPropertyNames();
}




public synchronized String toString() {
StringBuffer buffer = new StringBuffer();
Iterator<Map.Entry<String, String>> kvIter = keyCommentMap.entrySet().iterator();
buffer.append("[");
while(kvIter.hasNext()){
buffer.append("{");
Map.Entry<String, String> entry = kvIter.next();
String key = entry.getKey();
String val = getProperty(key);
String comment = entry.getValue();
buffer.append("key="+key+",value="+val+",comment="+comment);
buffer.append("}");
}
buffer.append("]");
return buffer.toString();
}


public boolean equals(Object o) {
//不考虑注释说明是否相同
return props.equals(o);
}


public int hashCode() {
return props.hashCode();
}

private void load0(LineReader lr) throws IOException {
char[] convtBuf = new char[1024];
int limit;
int keyLen;
int valueStart;
char c;
boolean hasSep;
boolean precedingBackslash;
StringBuffer buffer = new StringBuffer();


while ((limit = lr.readLine()) >= 0) {
c = 0;
keyLen = 0;
valueStart = limit;
hasSep = false;
//获取注释
c = lr.lineBuf[keyLen];
if(c == '#' || c == '!'){
String comment = loadConvert(lr.lineBuf, 1, limit - 1, convtBuf);
if(buffer.length() > 0){
buffer.append("\n");
}
buffer.append(comment);
continue;
}
precedingBackslash = false;
while (keyLen < limit) {
c = lr.lineBuf[keyLen];
//need check if escaped.
if ((c == '=' ||  c == ':') && !precedingBackslash) {
valueStart = keyLen + 1;
hasSep = true;
break;
} else if ((c == ' ' || c == '\t' ||  c == '\f') && !precedingBackslash) {
valueStart = keyLen + 1;
break;
} 
if (c == '\\') {
precedingBackslash = !precedingBackslash;
} else {
precedingBackslash = false;
}
keyLen++;
}
while (valueStart < limit) {
c = lr.lineBuf[valueStart];
if (c != ' ' && c != '\t' &&  c != '\f') {
if (!hasSep && (c == '=' ||  c == ':')) {
hasSep = true;
} else {
break;
}
}
valueStart++;
}
String key = loadConvert(lr.lineBuf, 0, keyLen, convtBuf);
String value = loadConvert(lr.lineBuf, valueStart, limit - valueStart, convtBuf);
setProperty(key, value, buffer.toString());
//reset buffer
buffer = new StringBuffer();
}
}


/* 
* 基于java.util.Properties.LineReader进行改造
* 
* Read in a "logical line" from an InputStream/Reader, skip all comment
* and blank lines and filter out those leading whitespace characters 
* (\u0020, \u0009 and \u000c) from the beginning of a "natural line". 
* Method returns the char length of the "logical line" and stores 
* the line in "lineBuf". 
*/
class LineReader {
public LineReader(InputStream inStream) {
this.inStream = inStream;
inByteBuf = new byte[8192]; 
}


public LineReader(Reader reader) {
this.reader = reader;
inCharBuf = new char[8192]; 
}


byte[] inByteBuf;
char[] inCharBuf;
char[] lineBuf = new char[1024];
int inLimit = 0;
int inOff = 0;
InputStream inStream;
Reader reader;


int readLine() throws IOException {
int len = 0;
char c = 0;


boolean skipWhiteSpace = true;
boolean isNewLine = true;
boolean appendedLineBegin = false;
boolean precedingBackslash = false;
boolean skipLF = false;


while (true) {
if (inOff >= inLimit) {
inLimit = (inStream==null)?reader.read(inCharBuf)
:inStream.read(inByteBuf);
inOff = 0;
if (inLimit <= 0) {
if (len == 0) { 
return -1; 
}
return len;
}
}     
if (inStream != null) {
//The line below is equivalent to calling a 
//ISO8859-1 decoder.
c = (char) (0xff & inByteBuf[inOff++]);
} else {
c = inCharBuf[inOff++];
}
if (skipLF) {
skipLF = false;
if (c == '\n') {
continue;
}
}
if (skipWhiteSpace) {
if (c == ' ' || c == '\t' || c == '\f') {
continue;
}
if (!appendedLineBegin && (c == '\r' || c == '\n')) {
continue;
}
skipWhiteSpace = false;
appendedLineBegin = false;
}
if (isNewLine) {
isNewLine = false;
}


if (c != '\n' && c != '\r') {
lineBuf[len++] = c;
if (len == lineBuf.length) {
int newLength = lineBuf.length * 2;
if (newLength < 0) {
newLength = Integer.MAX_VALUE;
}
char[] buf = new char[newLength];
System.arraycopy(lineBuf, 0, buf, 0, lineBuf.length);
lineBuf = buf;
}
//flip the preceding backslash flag
if (c == '\\') {
precedingBackslash = !precedingBackslash;
} else {
precedingBackslash = false;
}
}
else {
// reached EOL
if (len == 0) {
isNewLine = true;
skipWhiteSpace = true;
len = 0;
continue;
}
if (inOff >= inLimit) {
inLimit = (inStream==null)
?reader.read(inCharBuf)
:inStream.read(inByteBuf);
inOff = 0;
if (inLimit <= 0) {
return len;
}
}
if (precedingBackslash) {
len -= 1;
//skip the leading whitespace characters in following line
skipWhiteSpace = true;
appendedLineBegin = true;
precedingBackslash = false;
if (c == '\r') {
skipLF = true;
}
} else {
return len;
}
}
}
}
}


/*
* Converts encoded &#92;uxxxx to unicode chars
* and changes special saved chars to their original forms
*/
private String loadConvert (char[] in, int off, int len, char[] convtBuf) {
if (convtBuf.length < len) {
int newLen = len * 2;
if (newLen < 0) {
newLen = Integer.MAX_VALUE;
} 
convtBuf = new char[newLen];
}
char aChar;
char[] out = convtBuf; 
int outLen = 0;
int end = off + len;


while (off < end) {
aChar = in[off++];
if (aChar == '\\') {
aChar = in[off++];   
if(aChar == 'u') {
// Read the xxxx
int value=0;
for (int i=0; i<4; i++) {
aChar = in[off++];  
switch (aChar) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
value = (value << 4) + aChar - '0';
break;
case 'a': case 'b': case 'c':
case 'd': case 'e': case 'f':
value = (value << 4) + 10 + aChar - 'a';
break;
case 'A': case 'B': case 'C':
case 'D': case 'E': case 'F':
value = (value << 4) + 10 + aChar - 'A';
break;
default:
throw new IllegalArgumentException(
"Malformed \\uxxxx encoding.");
}
}
out[outLen++] = (char)value;
} else {
if (aChar == 't') aChar = '\t'; 
else if (aChar == 'r') aChar = '\r';
else if (aChar == 'n') aChar = '\n';
else if (aChar == 'f') aChar = '\f'; 
out[outLen++] = aChar;
}
} else {
out[outLen++] = (char)aChar;
}
}
return new String (out, 0, outLen);
}


private void store0(BufferedWriter bw, boolean escUnicode)
throws IOException{
synchronized (this) {
Iterator<Map.Entry<String, String>> kvIter = keyCommentMap.entrySet().iterator();
while(kvIter.hasNext()){
Map.Entry<String, String> entry = kvIter.next();
String key = entry.getKey();
String val = getProperty(key);
String comment = entry.getValue();
key = saveConvert(key, true, escUnicode);
/* No need to escape embedded and trailing spaces for value, hence
* pass false to flag.
*/
val = saveConvert(val, false, escUnicode);
if(!comment.equals(BLANK))
writeComments(bw, comment);
bw.write(key + "=" + val);
bw.newLine();
}
}
bw.flush();
}


private static void writeComments(BufferedWriter bw, String comments) 
throws IOException {
bw.write("#");
int len = comments.length();  
int current = 0;
int last = 0;
while (current < len) {
char c = comments.charAt(current);
if (c > '\u00ff' || c == '\n' || c == '\r') {
if (last != current) 
bw.write(comments.substring(last, current));
if (c > '\u00ff') {
bw.write(c);
} else {
bw.newLine();
if (c == '\r' && 
current != len - 1 && 
comments.charAt(current + 1) == '\n') {
current++;
}
if (current == len - 1 ||
(comments.charAt(current + 1) != '#' &&
comments.charAt(current + 1) != '!'))
bw.write("#");
}
last = current + 1;
} 
current++;
}
if (last != current) 
bw.write(comments.substring(last, current));
bw.newLine();
}


/*
* Converts unicodes to encoded &#92;uxxxx and escapes
* special characters with a preceding slash
*/
private String saveConvert(String theString,
boolean escapeSpace,
boolean escapeUnicode) {
int len = theString.length();
int bufLen = len * 2;
if (bufLen < 0) {
bufLen = Integer.MAX_VALUE;
}
StringBuffer outBuffer = new StringBuffer(bufLen);


for(int x=0; x<len; x++) {
char aChar = theString.charAt(x);
// Handle common case first, selecting largest block that
// avoids the specials below
if ((aChar > 61) && (aChar < 127)) {
if (aChar == '\\') {
outBuffer.append('\\'); outBuffer.append('\\');
continue;
}
outBuffer.append(aChar);
continue;
}
switch(aChar) {
case ' ':
if (x == 0 || escapeSpace) 
outBuffer.append('\\');
outBuffer.append(' ');
break;
case '\t':outBuffer.append('\\'); outBuffer.append('t');
break;
case '\n':outBuffer.append('\\'); outBuffer.append('n');
break;
case '\r':outBuffer.append('\\'); outBuffer.append('r');
break;
case '\f':outBuffer.append('\\'); outBuffer.append('f');
break;
case '=': // Fall through
case ':': // Fall through
case '#': // Fall through
case '!':
outBuffer.append('\\'); outBuffer.append(aChar);
break;
default:
if (((aChar < 0x0020) || (aChar > 0x007e)) & escapeUnicode ) {
outBuffer.append('\\');
outBuffer.append('u');
outBuffer.append(toHex((aChar >> 12) & 0xF));
outBuffer.append(toHex((aChar >>  8) & 0xF));
outBuffer.append(toHex((aChar >>  4) & 0xF));
outBuffer.append(toHex( aChar        & 0xF));
} else {
outBuffer.append(aChar);
}
}
}
return outBuffer.toString();
}


/**
* Convert a nibble to a hex character
* @param nibble the nibble to convert.
*/
private static char toHex(int nibble) {
return hexDigit[(nibble & 0xF)];
}


/** A table of hex digits */
private static final char[] hexDigit = {
'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'
};


}