printwriter | 易学教程

Java 字节流操作2

阅读更多关于 Java 字节流操作2

上篇文章 Java 字节流操作介绍了java中基本的字节流操作，但是我们常常对于字符操作，如果使用字节流来实现输入输出就显得麻烦，我们可以使用字符流来实现对我们看得见的字符char进行操作，主要内容如下：基本流（Reader/Writer）转换流（InputStreamReader/OutputStreamEWriter）文件字符流（FileReader/FileWriter）字符数组流（charArrayReader/charArrayWriter）缓冲字符流（BufferedReader/BufferedWriter）装饰类（PrintWriter）一、基本流字节流的基本流是InputStream/OutputStream，这里的字符流的基本流是Reader/Writer，他们都是抽象类，想要实现更加复杂的操作就必须要子类来扩充。他们内部主要的就是read和write方法，实现单个字符及字符数组的读取的写入。此处就不再列出，我们将会从他们的子类中看看这些方法的实现。二、转换流 InputStreamReader和OutputStreamWriter这两个类型流，在整个字符流中是十分重要的流，他们实现了和字节流的转换。先看看InputStreamReader: private final StreamDecoder sd; public

Python socket receives incomplete message from Java PrintWriter socket

阅读更多关于 Python socket receives incomplete message from Java PrintWriter socket

I made a python "queue" (similar to a JMS protocol) that will receive questions from two Java clients. The python-server will receive the message from one of the Java clients and the second one will read the question and post an answer. The connection and messaging works, the problem comes when a Java client answers with a String of great length. The response received by python is incomplete! What is worse, the message is cut at a certain number of characters and always at the same length, but, that number is different if someone else hosts the server. (i.e.: friend1 hosts the server, friend2

JSP Web过滤器入门2

阅读更多关于 JSP Web过滤器入门2

使用Web过滤器实现：将原始页面的内容修改后返回给客户端 ①index.jsp（使用入门1教程中的页面，无改动，任一一个JSP页面都可以） <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <%-- 这里的action使用的是相对路径,代表进入该路径--%> <form action="Login" method="post"> 用户：<input type="text" name="username"> 密码：<input type="password" name="userpwd"> <input type="submit" value="登录"> </form> </body> </html> ②继承了 HttpServletResponseWrapper 响应包装类的Java类： public class HttpResponseWrapper extends HttpServletResponseWrapper { // CharArrayWriter对象包含了返回的原始页面内容 private CharArrayWriter caw; // PrintWriter对象可以动态产生页面

Wanted but not invoke: Mockito PrintWriter

阅读更多关于 Wanted but not invoke: Mockito PrintWriter

Hi I am working on a project and using PrintWriter class for opening and writing in the file. But when I am writing the test case for same it gives following error at Line 153 Wanted but not invoked: mockPrintWriter.println("ID url1 "); -> at x.y.z.verify(ProcessImageDataTest.java:153) Actually, there were zero interactions with this mock. Code: (Uses Lombok Library) ProcessImageData.java @Setter @RequiredArgsConstructor public class ProcessImageData implements T { private final File newImageDataTextFile; @Override public void execute() { LineIterator inputFileIterator = null; try { File

Java - Understanding PrintWriter and need for flush

阅读更多关于 Java - Understanding PrintWriter and need for flush

Ok, firstly I apologise for all the code but I feel like too much code is better than not enough. I'm making a simple chat client and printwriter in particular i'm struggling with. With the code the way it is the now it will interact with the server class and perfectly fine and print what im wanting to print. However, when I remove 'writer.flush();' it will stop printing. With my understanding -which is evidently wrong- 'writer.println(outgoing.getText());' should be enough as this would send the text im trying to send to the server. I understand flush forces all the information to write but

Why FileWriter doesn't create a new file?

阅读更多关于 Why FileWriter doesn't create a new file?

问题 Consider the following code: m_Writer = new PrintWriter(new FileWriter("LoginHistory.dat")); m_Writer.println(Integer.toString(s_NumOfLogins)); m_Writer.println(m_LoginHistoryStr); m_Writer.close(); Any ideas why I don't find any file called LoginHistory.dat? Thanks Update: I've just found that I get an exception after line: m_Writer = new PrintWriter(new FileWriter("LoginHistory.dat")); and its details are: Any ideas what is the real problem? Listening for transport dt_shmem at address:

Why FileWriter doesn't create a new file?

阅读更多关于 Why FileWriter doesn't create a new file?

Consider the following code: m_Writer = new PrintWriter(new FileWriter("LoginHistory.dat")); m_Writer.println(Integer.toString(s_NumOfLogins)); m_Writer.println(m_LoginHistoryStr); m_Writer.close(); Any ideas why I don't find any file called LoginHistory.dat? Thanks Update: I've just found that I get an exception after line: m_Writer = new PrintWriter(new FileWriter("LoginHistory.dat")); and its details are: Any ideas what is the real problem? Listening for transport dt_shmem at address: tomcat_shared_memory_id 27/05/2012 15:52:17 org.apache.catalina.startup.HostConfig checkResources INFO:

PrintWriter create empty file

阅读更多关于 PrintWriter create empty file

问题 I have StringBuilder sb and I want that string save as *.txt file. Problem is that I get "filename.txt" but it is completely empty, also there is no errors in console. Here is my code: System.out.print(sb.toString()); PrintWriter out; try{ out = new PrintWriter("filename.txt"); out.println(sb.toString()); }catch (Exception e) { e.printStackTrace(); } Console output: [19/3/2014] Ime in priimek: Matjaz Mav Naslov: Ppot 6, 1000 Ljubljana Telefon: 040 111 222 Registerska št.: LJ 1234 Znamka:

Blank file after writing to it?

阅读更多关于 Blank file after writing to it?

So I have been trying to write a Bukkit plugin for a friend of mine, and for some reason the config generation is not working. The code in question is below, and I will be happy to add any code that people need to help me out with this. When I run the program, the config file that was created ends up blank. The testing file is just fine (I tested that by simply commenting out the line that deletes the file) but once I try to get multiple lines it fails. Can anyone help? PrintWriter out = new PrintWriter(new FileWriter(config)); out.println("########################################"); out

BS结构的一个注册用户的功能

阅读更多关于 BS结构的一个注册用户的功能

注册用户功能学了Java一段时间，就想折腾折腾，就做了一个注册的功能，用HTML写了一个网页上的比较简陋的界面，用Java做了一个后台简陋的服务器处理数据，最后将数据存储到数据库中。注册界面先是最简单的用HTML表单做一个简陋的界面，上一个效果图: 这块就直接上代码了，用到了HTML的表单，没有什么花里胡哨的渲染美化 <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title></title> </head> <body> <fieldset id=""> <legend>注册区域</legend>  <form action="http://192.168.37.1:10003" method="post"> <table border="1" bordercolor="blue" cellspacing="0" width="600" cellpadding="5"> <tr> <th colspan="2">注册页面</th> </tr> <tr> <td>用户名(U)：</td> <td><input type="text" name=

订阅 printwriter