java修改Properties文件,让输出格式与输入格式保持不变

 

 

 

在方法中调用

 

 

 

FileInputStream input = new FileInputStream("e:/input.properties");

       SafeProperties safeProp = new SafeProperties();

       safeProp.load(input);

       input.close();

       safeProp.addComment("New Comment");

       safeProp.put("New-Key", "New====Value");

       FileOutputStream output = new FileOutputStream("e:/output.properties");

       safeProp.store(output, null);

       output.close();

 

 

 

 

--------------------------------------------- SafeProperties类内容------------------------

 

 

 

 

 

 

 

 

 

 

 

 

 

package com.jianrc.util;

 

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

import java.util.Properties;

 

public class SafeProperties extends Properties {

private static final long serialVersionUID = 5011694856722313621L;

 

private static final String keyValueSeparators = "=: \t\r\n\f";

 

private static final String strictKeyValueSeparators = "=:";

 

private static final String specialSaveChars = "=: \t\r\n\f#!";

 

private static final String whiteSpaceChars = " \t\r\n\f";

 

private PropertiesContext context = new PropertiesContext();

 

public PropertiesContext getContext() {

return context;

}

 

public synchronized void load(InputStream inStream) throws IOException {

 

BufferedReader in;

 

in = new BufferedReader(new InputStreamReader(inStream, "8859_1"));

while (true) {

// Get next line

String line = in.readLine();

// intract property/comment string

String intactLine = line;

if (line == null)

return;

 

if (line.length() > 0) {

 

// Find start of key

int len = line.length();

int keyStart;

for (keyStart = 0; keyStart < len; keyStart++)

if (whiteSpaceChars.indexOf(line.charAt(keyStart)) == -1)

break;

 

// Blank lines are ignored

if (keyStart == len)

continue;

 

// Continue lines that end in slashes if they are not comments

char firstChar = line.charAt(keyStart);

 

if ((firstChar != '#') && (firstChar != '!')) {

while (continueLine(line)) {

String nextLine = in.readLine();

intactLine = intactLine + "\n" + nextLine;

if (nextLine == null)

nextLine = "";

String loppedLine = line.substring(0, len - 1);

// Advance beyond whitespace on new line

int startIndex;

for (startIndex = 0; startIndex < nextLine.length(); startIndex++)

if (whiteSpaceChars.indexOf(nextLine.charAt(startIndex)) == -1)

break;

nextLine = nextLine.substring(startIndex, nextLine.length());

line = new String(loppedLine + nextLine);

len = line.length();

}

 

// Find separation between key and value

int separatorIndex;

for (separatorIndex = keyStart; separatorIndex < len; separatorIndex++) {

char currentChar = line.charAt(separatorIndex);

if (currentChar == '\\')

separatorIndex++;

else if (keyValueSeparators.indexOf(currentChar) != -1)

break;

}

 

// Skip over whitespace after key if any

int valueIndex;

for (valueIndex = separatorIndex; valueIndex < len; valueIndex++)

if (whiteSpaceChars.indexOf(line.charAt(valueIndex)) == -1)

break;

 

// Skip over one non whitespace key value separators if any

if (valueIndex < len)

if (strictKeyValueSeparators.indexOf(line.charAt(valueIndex)) != -1)

valueIndex++;

 

// Skip over white space after other separators if any

while (valueIndex < len) {

if (whiteSpaceChars.indexOf(line.charAt(valueIndex)) == -1)

break;

valueIndex++;

}

String key = line.substring(keyStart, separatorIndex);

String value = (separatorIndex < len) ? line.substring(valueIndex, len) : "";

 

// Convert then store key and value

key = loadConvert(key);

value = loadConvert(value);

//memorize the property also with the whold string

put(key, value, intactLine);

} else {

//memorize the comment string

context.addCommentLine(intactLine);

}

} else {

//memorize the string even the string is empty

context.addCommentLine(intactLine);

}

}

}

 

/*

* Converts encoded &#92;uxxxx to unicode chars and changes special saved

* chars to their original forms

*/

private String loadConvert(String theString) {

char aChar;

int len = theString.length();

StringBuffer outBuffer = new StringBuffer(len);

 

for (int x = 0; x < len;) {

aChar = theString.charAt(x++);

if (aChar == '\\') {

aChar = theString.charAt(x++);

if (aChar == 'u') {

// Read the xxxx

int value = 0;

for (int i = 0; i < 4; i++) {

aChar = theString.charAt(x++);

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.");

}

}

outBuffer.append((char) value);

} else {

if (aChar == 't')

outBuffer.append('\t'); /* ibm@7211 */

 

else if (aChar == 'r')

outBuffer.append('\r'); /* ibm@7211 */

else if (aChar == 'n') {

/*

* ibm@8897 do not convert a \n to a line.separator

* because on some platforms line.separator is a String

* of "\r\n". When a Properties class is saved as a file

* (store()) and then restored (load()) the restored

* input MUST be the same as the output (so that

* Properties.equals() works).

* 

*/

outBuffer.append('\n'); /* ibm@8897 ibm@7211 */

} else if (aChar == 'f')

outBuffer.append('\f'); /* ibm@7211 */

else

/* ibm@7211 */

outBuffer.append(aChar); /* ibm@7211 */

}

} else

outBuffer.append(aChar);

}

return outBuffer.toString();

}

 

public synchronized void store(OutputStream out, String header) throws IOException {

BufferedWriter awriter;

awriter = new BufferedWriter(new OutputStreamWriter(out, "8859_1"));

if (header != null)

writeln(awriter, "#" + header);

List entrys = context.getCommentOrEntrys();

for (Iterator iter = entrys.iterator(); iter.hasNext();) {

Object obj = iter.next();

if (obj.toString() != null) {

writeln(awriter, obj.toString());

}

}

awriter.flush();

}

 

private static void writeln(BufferedWriter bw, String s) throws IOException {

bw.write(s);

bw.newLine();

}

 

private boolean continueLine(String line) {

int slashCount = 0;

int index = line.length() - 1;

while ((index >= 0) && (line.charAt(index--) == '\\'))

slashCount++;

return (slashCount % 2 == 1);

}

 

/*

* Converts unicodes to encoded &#92;uxxxx and writes out any of the

* characters in specialSaveChars with a preceding slash

*/

private String saveConvert(String theString, boolean escapeSpace) {

int len = theString.length();

StringBuffer outBuffer = new StringBuffer(len * 2);

 

for (int x = 0; x < len; x++) {

char aChar = theString.charAt(x);

switch (aChar) {

case ' ':

if (x == 0 || escapeSpace)

outBuffer.append('\\');

 

outBuffer.append(' ');

break;

case '\\':

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;

default:

if ((aChar < 0x0020) || (aChar > 0x007e)) {

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 {

if (specialSaveChars.indexOf(aChar) != -1)

outBuffer.append('\\');

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' };

 

public synchronized Object put(Object key, Object value) {

context.putOrUpdate(key.toString(), value.toString());

return super.put(key, value);

}

 

public synchronized Object put(Object key, Object value, String line) {

context.putOrUpdate(key.toString(), value.toString(), line);

return super.put(key, value);

}

 

 

public synchronized Object remove(Object key) {

context.remove(key.toString());

return super.remove(key);

}

 

class PropertiesContext {

private List commentOrEntrys = new ArrayList();

 

public List getCommentOrEntrys() {

return commentOrEntrys;

}

 

public void addCommentLine(String line) {

commentOrEntrys.add(line);

}

 

public void putOrUpdate(PropertyEntry pe) {

remove(pe.getKey());

commentOrEntrys.add(pe);

}

 

public void putOrUpdate(String key, String value, String line) {

PropertyEntry pe = new PropertyEntry(key, value, line);

remove(key);

commentOrEntrys.add(pe);

}

 

public void putOrUpdate(String key, String value) {

                   PropertyEntry pe = new PropertyEntry(key, value);  

                   int index = remove(key);  

                   commentOrEntrys.add(index,pe);   

}

 

public void remove(String key) {

                    for (int index = 0; index < commentOrEntrys.size(); index++) {  

                        Object obj = commentOrEntrys.get(index);  

                        if (obj instanceof PropertyEntry) {  

                           if (obj != null) {  

                             if (key.equals(((PropertyEntry) obj).getKey())) {  

                                commentOrEntrys.remove(obj);  

                                return index;  

                             }  

                        }  

                    }  

                 }  

            return commentOrEntrys.size();  

}

 

class PropertyEntry {

private String key;

 

private String value;

 

private String line;

 

public String getLine() {

return line;

}

 

public void setLine(String line) {

this.line = line;

}

 

public PropertyEntry(String key, String value) {

this.key = key;

this.value = value;

}

 

/**

* @param key

* @param value

* @param line

*/

public PropertyEntry(String key, String value, String line) {

this(key, value);

this.line = line;

}

 

public String getKey() {

return key;

}

 

public void setKey(String key) {

this.key = key;

}

 

public String getValue() {

return value;

}

 

public void setValue(String value) {

this.value = value;

}

 

public String toString() {

if (line != null) {

return line;

}

if (key != null && value != null) {

String k = saveConvert(key, true);

String v = saveConvert(value, false);

return k + "=" + v;

}

return null;

}

}

}

 

/**

* @param string

*/

public void addComment(String comment) {

if (comment != null) {

context.addCommentLine("#" + comment);

}

}

 

}