在 servlet 中写入文件时出错

Question

我已经通过 servlet 中的 doPost 方法创建了一个文件，但我无法将数据写入其中。我无法弄清楚错误是什么。顺便说一下，文件正在创建

// TODO Auto-generated method stub
        response.setContentType("text/html");
        String name=request.getParameter("name");
        response.getWriter().println(name);
        File filename= new File("/home/ksampath/D3/DedupeEngine/cache3.txt");
        filename.createNewFile();
        BufferedWriter out = null;
        try
        {
            System.out.println("I am going to create a new file");
            FileWriter fw=new FileWriter("cache3.txt",true);
            out=new BufferedWriter(fw);
            out.write("hello world");
            out.write(name);
        }

        catch(IOException e)
        {
            System.err.println("Error"+ e.getMessage());
        }
        finally
        {
            if(out!=null)
            {
                out.close();
            }
        }
        /*
        System.out.println("Lets us check whether it works");
        PrintWriter writer=response.getWriter();
        writer.println("<h3>hello This is my first servlet</h3>");*/
    }

Answer 1

尝试

FileWriter fw=new FileWriter(filename,true);   //where filename is that File object

public FileWriter(File file, boolean append) throws IOException

Constructs a FileWriter object given a File object. If the second argument is true, then bytes will be written to the end of the file rather than the beginning.

Java Docs

Answer 2

@singhakash 提供的解决方案是正确的。

您可以使用

FileWriter fw=new FileWriter(filename,true);

并且如前所述，如果第二个参数为真，则将在末尾附加字节。

或者你可以使用getAbsoluteFile()File的方法，这样

FileWriter fw=new FileWriter(filename.getAbsoluteFile());

The getAbsoluteFile()method will return, The absolute abstract pathname denoting the same file or directory as this abstract pathname(JavaDocs)

在 servlet 中写入文件时出错

Error in wrting file in servlet

java

jsp

servlets

file