Java应用之删除注释和英文大小写转换
??? 最近写博客上传代码的时候，用于代码里写了些很随意的注释，想把注释全部删掉，在网上找了下代码，发现很多都是使用正则表达式替换的，如
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Map<String, String> patterns = new HashMap<String, String>();patterns.put("([^:])\\/\\/.*", "$1");// 匹配在非冒号后面的注释，此时就不到再遇到http://patterns.put("\\s+\\/\\/.*", "");// 匹配“//”前是空白符的注释patterns.put("^\\/\\/.*", "");patterns.put("^\\/\\*\\*.*\\*\\/$", "");patterns.put("\\/\\*.*\\*\\/", "");patterns.put("/\\*(\\s*\\*\\s*.*\\s*?)*\\*\\/", "");??? 使用过程中发现，这样替换是有问题的，如下上测试例子：
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/** * 这是注释//嵌套注释 * * @author Administrator 测试 修改日期:2014-02-17 */public class 测试注释 {/** * 测试注释 <[CDATA\**测试]> * * @param fileName * @param outFileName */public void TestFile(String fileName, String outFileName) {/** * 输出语句测试 */System.out.println("/*我是正常内容*/");// 测试注释L16/* 测试注释L17 */System.out.println("//注释哈哈");//今天是2014-02-17System.out.println("/*" + "* 测试" + //注释，能删除吗 /*测试L20*/ "注释*/");}}?? 这种正则替换的结果是：
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???? 正常内容也被替换掉了，所以在替换之前要先判断是否是在" "里面。
???? 在网上找了个靠谱点的代码，先上参考链接：
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http://jdksummer.iteye.com/blog/976707
??? 他的方法是先判断是否在""内再替换。如下：
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public void run(String inputF,String outputF) throws IOException { this.inputFile=inputF; this.outputFile=outputF; File file = new File(inputFile); if (!file.exists() || file.isDirectory()) { throw new FileNotFoundException(); } // 写出文件初始 File writefile = new File(outputFile); if (!writefile.exists()) { writefile.createNewFile(); } BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(writefile))); BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file))); boolean flagFindhead = true; // 多行注释找头 boolean markFinded = false; //是否发现双引号 int i = 0; String temp = null; temp = br.readLine(); while (temp != null) { if (temp != null) { StringBuilder sb = new StringBuilder(); for (i = 0; i < temp.length(); i++) { //此处一定要注意判断是否在双引号内 if (temp.charAt(i) == '/' && !(i > 0 && markFinded)) { if (i + 1 < temp.length() && temp.charAt(i + 1) == '/') { break; } else if (flagFindhead && i + 1 < temp.length() && temp.charAt(i + 1) == '*') { flagFindhead = false; for (int j = i + 1; j < temp.length(); j++) { i = j; if (temp.charAt(j) == '*' && (j + 1 < temp.length() && temp.charAt( j + 1) == '/')) { flagFindhead = true; i += 2; break; } } } } if (!flagFindhead && temp.charAt(i) == '*' && (i + 1 < temp.length() && temp.charAt(i + 1) == '/')) { flagFindhead = true; i += 2; } if (flagFindhead && i < temp.length()) { //发现双引号“ ，置发现标志为true，即进入了双引号的范围 if(temp.charAt(i)=='"' && markFinded==false) markFinded=true; //发现双引号” ，置发现标志为false，即已经出了双引号的范围 else if(temp.charAt(i)=='"' && markFinded==true) markFinded=false; sb.append(temp.charAt(i)); } } temp = sb.toString(); } if (temp.length() > 0) { bw.write(temp + "\r\n"); bw.flush(); } temp = br.readLine(); } br.close(); bw.close(); }?? 使用后发现文件中出现很多的空白，我修改了下，把空白行去掉了。
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public void delFileComment(String inputFile, String outputFile,String charSet)throws IOException {if(charSet==null){charSet="utf-8";}File file = new File(inputFile);if (!file.exists() || file.isDirectory()) {throw new FileNotFoundException();}BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outputFile),charSet));BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(file),charSet));boolean flagFindhead = true; // 多行注释找头boolean markFinded = false; // 是否发现双引号int i = 0;String temp = null;temp = br.readLine();while (temp != null) {if (temp != null) {StringBuilder sb = new StringBuilder();for (i = 0; i < temp.length(); i++) {// 此处一定要注意判断是否在双引号内if (temp.charAt(i) == '/' && !(i > 0 && markFinded)) {if (i + 1 < temp.length() && temp.charAt(i + 1) == '/') {break;} else if (flagFindhead && i + 1 < temp.length()&& temp.charAt(i + 1) == '*') {flagFindhead = false;for (int j = i + 1; j < temp.length(); j++) {i = j;if (temp.charAt(j) == '*'&& (j + 1 < temp.length() && temp.charAt(j + 1) == '/')) {flagFindhead = true;i += 2;break;}}}}if (!flagFindhead&& temp.charAt(i) == '*'&& (i + 1 < temp.length() && temp.charAt(i + 1) == '/')) {flagFindhead = true;i += 2;}if (flagFindhead && i < temp.length()) {// 发现双引号“ ，置发现标志为true，即进入了双引号的范围if (temp.charAt(i) == '"' && markFinded == false)markFinded = true;// 发现双引号” ，置发现标志为false，即已经出了双引号的范围else if (temp.charAt(i) == '"' && markFinded == true)markFinded = false;sb.append(temp.charAt(i));}}temp = sb.toString();}// 把空白换成""，然后使用trim过滤掉。temp = temp.replaceAll("\\s*\n", "");if (temp.trim().length() > 0) {bw.write(temp + "\r\n");bw.flush();}temp = br.readLine();}br.close();bw.close();}??? 测试结果如下：
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??? 结果很正确。
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??? 写博客中遇到的另一个问题是我的SQL语句有时候没注意，一会大写，一会小写，一点也不规范，所以自己写了个简单的类，把文件转换大写或者小写。
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public void convertContentTLowerCase(String fileName, String chartSet) {convertContent(fileName, true, chartSet);}public void convertContentTUpperCase(String fileName, String chartSet) {convertContent(fileName, false, chartSet);}public void convertContent(String fileName, boolean isLower, String chartSet) {if (chartSet == null) {chartSet = "utf-8";}String outFileName = fileName.substring(0, fileName.lastIndexOf("."))+ "_result" + fileName.substring(fileName.lastIndexOf("."));BufferedReader br = null;BufferedWriter bw = null;try {br = new BufferedReader(new InputStreamReader(new FileInputStream(fileName), chartSet));bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFileName), chartSet));String tempStr = null;while ((tempStr = br.readLine()) != null) {if (isLower) {tempStr = tempStr.toLowerCase();} else {tempStr = tempStr.toUpperCase();}bw.write(tempStr + "\r\n");}bw.flush();} catch (Exception e) {e.printStackTrace();} finally {try {if (br != null) {br.close();}if (bw != null) {bw.close();}} catch (IOException e) {e.printStackTrace();}}}?? 上面要2个路径是因为我我想读一行写一行?，核心就是String的toUpperCase。
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????? 上面的代码都很简单，这是我自己用的，请不要询问我有什么意义，对我我用就是意义，谢谢。
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????? 全文完。
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String s4 = "hi"; // "ni hao"String s1 = "hi/*ni hao */"; String s2 = "hi // ni hao";String s3 = "hi"; String s4 = "hi"; String s5 = "hi";