java读取写入文件指定编码

String charEncoding = "UTF-8";
    	
    	String path = request.getRealPath("/body/js/district.js");
    	StringBuilder sbl = new StringBuilder();
    	String end = "";
    	InputStreamReader isr = null;
    	BufferedReader bufferedReader = null;
        try {
            isr = new InputStreamReader(new FileInputStream(path), charEncoding);
            
            bufferedReader = new BufferedReader(isr);
            if ((end = bufferedReader.readLine()) != null) {
            	sbl.append(end);
            }
        } catch (FileNotFoundException ex) {ex.printStackTrace();
        	ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        }finally{
        	if(isr != null){
        		try {
        			isr.close();
					bufferedReader.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
        	}
        	if(bufferedReader != null){
        		try {
					bufferedReader.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
        	}
        }
        
        String newStr = AddressDeal.getNewPcdStr();
    	String content = sbl.toString();
    	int start = content.indexOf("var allDists=");
    	String newCont = content.substring(0,start);
    	newCont += "var allDists="+newStr+";";
    	
    	FileOutputStream fos = null;
    	OutputStreamWriter writer= null;
        try {
        	fos = new FileOutputStream(new File(path)) ;           
            writer = new OutputStreamWriter(fos,charEncoding); 
            writer.write(newCont);
        }catch (IOException ex) {  
        	ex.printStackTrace();
        }finally{
        	if(writer != null){
        		try {
        			writer.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
        	}
        	if(fos != null){
        		try {
        			fos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
        	}
        }