printwriter

how to clear contents of a PrintWriter after writing

由 試著忘記壹切 提交于 2019-12-19 05:50:56
问题 Good evening, i want to know how to clear the data written to a PrintWriter, i.e. is it possible to remove the data from a PrintWriter after printing? here in this servlet i print some text to the response and at the line denoted by # i want to remove all the previously printed data and print new stuff: protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { PrintWriter out = response.getWriter(); String uName = request

what is PrintWriter out = response.getWriter() in servlet

由 喜欢而已 提交于 2019-12-18 11:20:09
问题 I am new to Servlets. please tell me about this line: and doing in jersey framework + REstful web services. Any help regarding Jersey framework PrintWriter out = response.getWriter(); 回答1: In servlets the output can be either character or byte. for character data (i.e text) u can use PrintWriter for others use ServletOutputStream PrintWriter: prints text data to a character stream. getWriter :Returns a PrintWriter object that can send character text to the client. 回答2: in this case, the

what is PrintWriter out = response.getWriter() in servlet

由 独自空忆成欢 提交于 2019-12-18 11:20:04
问题 I am new to Servlets. please tell me about this line: and doing in jersey framework + REstful web services. Any help regarding Jersey framework PrintWriter out = response.getWriter(); 回答1: In servlets the output can be either character or byte. for character data (i.e text) u can use PrintWriter for others use ServletOutputStream PrintWriter: prints text data to a character stream. getWriter :Returns a PrintWriter object that can send character text to the client. 回答2: in this case, the

Java PrintWriter not working

由 假如想象 提交于 2019-12-17 14:55:23
问题 I am simply trying to write my 2d array "puzzle" to a file. I have a double for loop which reads through each of the 'char' values in my array and supposedly writes them to the file. I can't seem to find the error in my code. The file says it is modified when I run the program, but it is still blank. Thanks guys! public void writeToFile(String fileName) { try{ PrintWriter pW = new PrintWriter(new File(fileName)); for(int x = 0; x < 25; x++) { for(int y = 0; y < 25; y++) { pW.write(puzzle[x][y

MQ简易实现

由 末鹿安然 提交于 2019-12-16 19:16:41
消息处理中心： public class Broker { // 最大存储数 private final static int MAX_SIZE = 3; // 保存消息的容器 private static ArrayBlockingQueue<String> messageQueue = new ArrayBlockingQueue<>(MAX_SIZE); // 生产消息 public static void produce(String msg) { if (messageQueue.offer(msg)) { System.out.println("成功向消息中心发消息：" + msg + "，当前容量为：" + messageQueue.size()); } else { System.out.println("消息中心超负荷"); } System.out.println("-----------------"); } // 消费消息 public static String comsume() { String msg = messageQueue.poll(); if (msg != null) { System.out.println("得到消息：" + msg + "，当前容量为：" + messageQueue.size()); } else { System

How to write more than once to text file using PrintWriter

由 一世执手 提交于 2019-12-14 03:49:13
问题 I know how to create a PrintWriter and am able to take strings from my gui and print it to a text file. I want to be able to take the same program and print to the file adding text to the file instead of replacing everything already in the text file. How would I make it so that when more data is added to the text file, it is printed on a new line every time? Any examples or resources would be awesome. 回答1: try { PrintWriter out = new PrintWriter(new BufferedWriter(new FileWriter("outfilename"

cannot write in the file [closed]

由 一个人想着一个人 提交于 2019-12-13 22:16:10
问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 6 years ago . good day guys, im creating a program that will write the data to a text file. the data is coming from an array list, it is a data that is solved from the array list e.g : public double getGincome(){ gincome=rpd

Display online users from server to all connected clients

由 女生的网名这么多〃 提交于 2019-12-13 17:14:35
问题 I'm building simple socket server-client application consisting of: Server project (which creates new client handler thread when socket is accepted) and a Client project (which establishing connection with the server and displaying gui with message thread open). So far I'm able to connect using multiple clients and chat with no problems. I've set a command called !getusers that should display all connected users to the requesting client. When I do so, I'm suddenly unable to continue and chat,

Function stops my program

由 半世苍凉 提交于 2019-12-13 09:18:40
问题 I am trying to use the print function of PrintWriter. When I use this method, my program continues to run but all my other functions doesn't work. public void printVertices(PrintWriter os) { for(int i = 0; i < vert.size(); i++) { os.print(vert.get(i) + " "); } os.close(); } 回答1: Again, the problem is that you close the PrintWriter , which also closes the underlying OutputStream or Writer . You probably added the os.close(); statement, because otherwise the PrintWriter will buffer the output

Eclipse PrintWriter no file created [duplicate]

由 拜拜、爱过 提交于 2019-12-13 07:32:42
问题 This question already has answers here : java PrintWriter cannot be resolved (2 answers) Closed 5 years ago . OK so now I have this import java.io.*; public class driver { public static void main(String[] args) { PrintWriter out = null; try { out = new PrintWriter("output.txt"); } catch (FileNotFoundException e) { System.out.print("file not found"); e.printStackTrace(); } out.print("hello"); out.close(); } } Why doesn't eclipse create a file once I run the program? 回答1: Look in your working
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