Question

这个方法没有返回有效的字符串。可能是什么原因??

static BufferedWriter writer = null;
static int maxlines = 100;
public static String getTrimmedResponse(BufferedReader b) 
{

    try {

        int count = 0;
        writer = new BufferedWriter(new StringWriter());

        for (String  line; (line = b.readLine()) != null;) {
            if (count++ % maxlines == 0) 


            line = line.replaceAll("\\n", "");

            String trimmedLine = line.trim();
            if (trimmedLine.charAt(trimmedLine.length() - 1) == '>')
                writer.append(trimmedLine);
            else    
            writer.write(line);
            writer.newLine();
        }



    } catch (IOException e) {
        e.printStackTrace();
        Log.i("texception", e+"");
    }
    return writer.toString();

}

Answer 1

@Payal问题在您的退货声明中

writer.toString();

它返回writer对象的地址。你应该做的是：

StringWriter strWriter = new StringWriter();
 writer = new BufferedWriter(strWriter);

和

return strWriter.toString();

Answer 2

使用StringWriter获取回复，不要忘记刷新。

这是你的方法，有一些正确的格式：

static BufferedWriter writer = null;

public static String getTrimmedResponse(BufferedReader b) 
{
    StringWriter sw = new StringWriter();
    writer = new BufferedWriter(sw);
    int count = 0;

    try {

        for (String  line; (line = b.readLine()) != null;) {
            if (count++ % maxlines == 0) {
                line = line.replaceAll("\\n", "");
            }

            String trimmedLine = line.trim();
            if (trimmedLine.charAt(trimmedLine.length() - 1) == '>') {
                writer.append(trimmedLine);
            } else {
                writer.write(line);
                writer.newLine();
            }
        }

        //writer.flush();

    } catch (IOException e) {
        e.printStackTrace();
                    Log.i("texception", e+"");
    } finally {
        try {
                            // close flushes before closing
            writer.close();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
    return sw.toString();
}

Answer 3

原因是您尝试将BufferedWriter输出为字符串而不是它包装的StringWriter。正确的习语看起来像这样：

StringWriter sw = new StringWriter();
BufferedWriter writer = new BufferedWriter( sw );
... do your writing into writer ...
return sw.toString();

P.S。：一般来说，在尝试使用结果之前，flush() BufferedWriter是个好主意。或者甚至更好，close()它。你甚至可以关闭你的StringWriter，即使在这种情况下没有任何区别，关闭你的流和作家是一个很好的习惯。

Answer 4

writer是一个缓冲的作家。在缓冲的writer上调用toString将返回BufferedWriter类实例的字符串表示形式：

java.io.BufferedWriter@1e311410

如果您在底层toString实例上调用StringWriter，您将获得写入编写器的字符串数据。

存储在字符串中

4 个答案: