替换一个文件内的某个字符

public static void main(String[] args) throws IOException {
        
        try {
            FileReader r = new FileReader("d:/ti.txt");
        StringBuilder sb = new StringBuilder();
        char[] temp = new char[1];
        int read = r.read(temp);
        while(read!=-1){
            sb.append(temp);
        }
        String strAfter = sb.toString().replace("c", "x");
        FileWriter w = new FileWriter("d:/titi.txt");
        w.write(strAfter);
        r.close();
        w.close();
            
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

public static void main(String[] args) throws IOException {
        
        try {
            FileReader r = new FileReader("d:/ti.txt");
        StringBuilder sb = new StringBuilder();
        char[] temp = new char[1];
        //r.read(temp)放到while的里
        while((r.read(temp))!=-1){
            sb.append(temp);
        }
        String strAfter = sb.toString().replace("c", "x");
        FileWriter w = new FileWriter("d:/titi.txt");
        w.write(strAfter);
        r.close();
        w.close();
            
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }