Question

我正在运行以下servlet，我在浏览器上得到一些奇怪的输出。程序工作正常，没有任何错误但由于某种原因，行out.println(Add_To_Queue("abc","xyz","pqr"));的输出显示以java字符串的形式，如下所示代码：

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        try {
            out.println("<!DOCTYPE> html");  // HTML 5
            out.println("<html><head>");
            out.println("<meta http-equiv='Content-Type' content='text/html; charset=UTF-8'>");
            out.println(Test_Servlet("abc","xyz","pqr"));
            out.println("<head><title>TEST SERVLET API Call</title></head>");
            out.println("<body>");
            out.println("<h3>TEST SERVLET</h3>");

            // Tabulate the request information 
            out.println("</body></html>");
        }   
        finally {
            out.close();  // Always close the output writer
        }
    }

      public static Object Test_Servlet(String FirstString,String Secondstring,String ThirdString) throws IOException {
        String accessKey = "myaccesskey";
        String secretKey = "mysecretkey";
        String uRLCppList = "http://myurl.com";
        String method = "POST";
        java.util.Date currentTime = new java.util.Date();
        SimpleDateFormat sdf = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss z");

        // Give it to me in GMT time.
        sdf.setTimeZone(TimeZone.getTimeZone("GMT"));
        String dateTimeString = sdf.format(currentTime);

        String signature = generateSignature(method, secretKey, dateTimeString);
        String authorization = accessKey + ":" + signature;
        Map<String, String> params = new HashMap<String, String>();

        params.put("Content of first String", FirstString);
        params.put("Content of Second String", Secondstring);
        params.put("Content of Third String", ThirdString);

        String[] result = sendHttpRequest(uRLCppList, "POST", params, dateTimeString, authorization);

        return result;
    }

以下是浏览器输出：

html [Ljava.lang.String;@430bc84a
TEST SERVLET

我正在使用JDK 8，ApacheTomcat 6，Netbeans 7.4进行部署。我怀疑，在result方法中定义的变量Test_Servlet中返回的结果无法在Web浏览器上正确显示。

SendHttpRequest方法的附加代码：

public static String[] sendHttpRequest(String requestUrl, String method, Map<String, String> params, String dateTimeString, String authorization) throws IOException {
        List<String> response = new ArrayList<String>();
        StringBuffer requestParams = new StringBuffer();

        if (params != null && params.size() > 0) {
            Iterator<String> paramIterator = params.keySet().iterator();
            while (paramIterator.hasNext()) {
                String key = paramIterator.next();
                String value = params.get(key);
                requestParams.append(URLEncoder.encode(key, "UTF-8"));
                requestParams.append("=").append(URLEncoder.encode(value, "UTF-8"));
                requestParams.append("&");
            }
        }
        URL url = new URL(requestUrl);
        URLConnection urlConn = url.openConnection();
        urlConn.setRequestProperty("accept", "application/json");
        urlConn.setRequestProperty("datetime", dateTimeString);
        urlConn.setRequestProperty("authorization", authorization);
        urlConn.setUseCaches(false);

        // the request will return a response
        urlConn.setDoInput(true);

        if ("POST".equals(method)) {
            // set request method to POST
            urlConn.setDoOutput(true);
        } else {
            // set request method to GET
            urlConn.setDoOutput(false);
        }

        if ("POST".equals(method) && params != null && params.size() > 0) {
            OutputStreamWriter writer = new OutputStreamWriter(urlConn.getOutputStream());
            writer.write(requestParams.toString());
            writer.flush();  
        }

        // reads response, store line by line in an array of Strings
        BufferedReader reader = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));

        String line = "";
        while ((line = reader.readLine()) != null) {
            response.add(line);
        }
        reader.close();
        return (String[]) response.toArray(new String[0]);
    }

Answer 1

您的Test_Servlet方法返回的数组String。在数组上调用toString()的结果是你得到的字符串，其中包括类型和对象Id。

不确定你要做什么，但你可以通过遍历返回的数组来放出字符串。

Answer 2

html [Ljava.lang.String;@430bc84a

html来自您需要关闭代码的out.println("<!DOCTYPE> html");。

[Ljava.lang.String;@430bc84a是字符串数组的toString的默认值，告诉您引用的存在位置。 [ - 表示数组以及后面的类型恰好是java.lang.String。这是JVM级别输出

我做的事情如下：

String resultStr = ""; for(String s: result){ //format however you wish, this separates each element by a space resultStr += s + " "; } return resultStr

如果要将结果放在表或其他内容中，可以返回数组并使用相同的for循环来封装标记中的每个元素。选择是你的，并且工作正常

测试servlet时在浏览器输出上获取字符串

2 个答案: