I'm using Ubuntu. After unpacking the tar file for JSE 1.7 version 45, in the the bin directory for adding an entry to PATH variable, I typed
javac
and I get the message
The program 'javac' can be found in the following packages:
* default-jdk
* ecj
* gcj-4.6-jdk
* gcj-4.7-jdk
* openjdk-7-jdk
* openjdk-6-jdk
Try: sudo apt-get install <selected package>
Do I have to install these ?
I use Javassist to manually add a exception table entry:
Java Code:
MethodInfo minfo = (MethodInfo) aclasscf.getMethods().get(0);
CodeAttribute ca = minfo.getCodeAttribute();
ExceptionTable et = ca.getExceptionTable();
et.add(26, 30, 40, 0);
System.out.println("exception table size: " + et.size()); mh_sh_highlight_all('java');
If I get the bytecode with javap it seems to work:
Java Code:
Exception Table
from to target type
26 30 40 any mh_sh_highlight_all('java');
But the problem is that I can't run the file anymore. Simply running it with the java command results in "java.lang.VerifyError: Expecting a stackmap frame at branch target 40". After some research this seems to be a problem with java 7 and a stricter verifier. I read several times that java -XX:-UseSplitVerifier should be used instead.
This really fixed the stackmap error, but then another error appeared: "java.lang.VerifyError: (class: AClass, method: signature: ()V) Inconsistent stack height 2 != 1". Are there any further steps required to insert a new exception in the exception table?
Additional info: Later I want to remove gotos (in this case the goto at line 27) and add a function call instead. When this function finishes it will throw a exception and propagate it back to the caller (which will be at line 27). Then the program should go on as if nothing happend, that is also the reason why the target of the exception is the same as the target of the goto (40)
Here is the bytecode:
Java Code:
0: aload_0
1: invokespecial #8 // Method java/lang/Object."<init>":()V
4: iconst_0
5: istore_1
6: goto 19
9: getstatic #10 // Field java/lang/System.out:Ljava/io/PrintStream;
12: iload_1
13: invokevirtual #16 // Method java/io/PrintStream.println:(I)V
[Code] .....
Exception table:
from to target type
26 30 40 any mh_sh_highlight_all('java');
Can we set the class path for one level down the current directory? My structure is like
binlibresourceshexicon.cmdinside the folder dist.
In this case I could run the .cmd file which has java -cp .;lib;resources client.Test .
c: rycpdist>java hexicon.cmdBut if i put the .cmd file inside bin as like this and run as
c: rycpdistin>java hexicon.cmdI am getting this error Error: Could not find or load main class
Is there any possibility to set the class path in this case
I need to write the exact directory path like C:LisaestUpdate to a properties file.
I am trying it by
FileInputStream in = new FileInputStream(test.properties);
Properties props = new Properties();
props.load(in);
in.close();
FileOutputStream out = new FileOutputStream(newprop.properties);
props.setProperty("myDirectory","C:Lisa estUpdate" );
props.store(out, null);
out.close();
but the properties file is updated as C:Lisa estUpdate
Extra comes before :.
How can I remove that.
Even I tried it with an command but got same output.
I'm having another issue. I have 2 java source files(see below). They are place in the same directory. How do I compile them using classpath?
I have already tried 1st attempt :
javac -cp com.companyname.interview.DuplicateReplace.java DuplicateReplaceTest.java [did not work!]
2nd attempt: javac -cp DuplicateReplace.java DuplicateReplaceTest.java [again, did not work!]
package com.companyname.interview;
public class DuplicateReplace { /* code */}
[Code] ....
I'm using a PrimeFaces UploadedFile xhtml page to select a csv file to read and write using a managed bean (SuperCSVParser.java). The file is read and written to an entity class which then persists the data to a database. The application works fine if I specify a file path on the physical server and select a csv file on that file path. But for the production version I want the user to select ANY file name from ANY directory on their local system.
I know about the FacesContext methods and I've looked at some methods from the java.io File class. Most of these methods are about getting the path from the server, where I want to 'pass' the path String from the client machine to allow the uploaded file to go through. When I try with the below code I get:
java.io.FileNotFoundException: data.csv (The system cannot find the file specified)
I'd like to know what I'm doing as I prefer not to explicitly declare a path in the final app. I'm almost sure that's possible.
<h:form enctype="multipart/form-data">
<p:fileUpload value="#{SuperCsvParser.file}"
mode="simple"
auto="true"
[Code].....
I have BlueJ installed on my computer and it does the job of compiling the java source code written in it. If I want to write and compile source code outside of BlueJ do I still need to download the Java SDK and set the PATH variable, even though I am apparently able to do it in BlueJ?
View Replies View RelatedCan I add a variable to Windows PATH from java code?
View Replies View Relatedthis is the following task i am trying to do. Write an interface Directory to manipulate entries in a telephone directory for the University. The interface must support the following operations:
1) The ability to insert new entries into the directory. Entries should be stored in alphabetical order of surname.
2) Delete entries from the directory either by name or number
3) Provide a lookup method that will find the extension no of a member of staff given
his/her name. You should try to make this method run as efficiently as possible.
4) Change a person's telephone number
5) Print the telephone directory in a neatly tabulated fashion.
Write a class ArrayDirectory that implements this interface using an array to store the telephone directory information. The class must store the surname and initial for each member of staff and their telephone extension (a four digit number which may start with a zero). You may find it useful to define a class Entry to store information about individual entries. The entries should be read into the array from a text file consisting of multiple lines in the following format:
Surname<tab>Initials<tab>Telephone extension
The part that i am stuck on is trying to do the entry method, delete entries method, loop up method, change persons telephone number and be able to print it.
Consider the url-pattern:
<url-pattern> /Beer/* </url-pattern>
The web app structure is: -
webapps
|
-->AdviceApp
|
-->WEB-INF
--> {{Beer}} This can be real or virtual.
My book says that /Beer/* can be a real or a virtual directory. What is the difference between the two and how do I create a virtual directory in tomcat ?
I am copying the xml files from one folder to other folder, in the source folder, i have some files which have some content like "backing File="$IDP_ ROOT/metadata/iPAU-SP-metadata.xml" but while writing to the destination folder.i am replacing the "$IDP_ROOT" with my current working directory. The entire copying of files is for deploying into tomcat server. The copying is done only when server starts for the first time.Problem: If i change the folder name from my root path in my machine after i run the server,the entire process will be stopped because the destination folder files already contains the content which is with existed files names or folder names.
So i want to change it to relative path instead absolute path. What is the best way to do it? Please look at code below:
[ // Getting the current working directory
String currentdir = new File(".").getAbsoluteFile().getParent() + File.separator;
if(currentdir.indexOf("ControlPanel")!=-1){
rootPath=currentdir.substring(0, currentdir.indexOf("ControlPanel"));
}else{
rootPath=currentdir;
[code]....
Is it possible to check to see if a what a user has entered is a string or a other variable type, if I'm asking this the right way?
View Replies View Relatedbecause of the need to implement a certain software watermarking technique I have to manipulate the exception table.
(Link to the paper that describes the technique: [URL] .... (Section "Extension to Java Bytecode")
So far I could manually add the exception table entry with Javassist:
MethodInfo minfo = (MethodInfo) aclasscf.getMethods().get(0);
CodeAttribute ca = minfo.getCodeAttribute();
ExceptionTable et = ca.getExceptionTable();
[Code]....
I'd like to know is there a way to restrict a user from inputting certain characters into a TextField? Is there something like isNumeric() available?
In Visual Basic, I was able to prevent the user entering certain characters of my choice into each textbox, however I've looked and I haven't been able to find a solution. I've tried using the following else if as part of an if statement:
else if (txtEmployeeName.getText().contains("[0-9]+"){ }
but it doesn't seem to work.
I have an env-entry defined in my web.xml and when I attempt to print it from a simple servlet all I get is null. And of course if I attempt to invoke any methods on the object I get a NullPointerException.I read somewhere that this can happen if you're using version 2.4 instead of 2.5, so I changed to 2.5 and I still have the same issue. Here's the web.xml:
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.5"
xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_5.xsd">
<display-name>ResourceTest</display-name>
<servlet>
[code]....
I have a JSF application with this code in the xhtml page:
<h:selectOneListbox id="selectProduct" size="10" style="width:10em; font-family:monospace" value="#{mybean.product}">
<f:selectItems value="#{mybean.products}" />
</h:selectOneListbox>
and the corresponding snippets of the Java code are:
// Class member variables
// ...
private String product;
private ArrayList<String> productValues;
private ArrayList<String> productLabels;
private SelectItem[] products;
// ... Various properties etc.
public String getLocation() { // Displayed on a page
[code]....
Most of this works correctly using only ArrayList SelectItem products without the two ArrayList and the separate SelectItem[], and the values and labels are put directly into products here. The menu works and I can select an item. However, I am unable to find the correct method for finding the index in the submit method,namely:
public void submit(ActionEvent e) {
showProduct = true;
prodNum = products.indexOf(product); // --- Here is the problem!
updateProduct();
}
which has not been changed here. In spite of trying out various ideas, prodNum always returns with -1, which means it cannot find the index of the selected product, where product is a String. Everything else seems to work correctly, and products.get(prodNum).getLabel() works if I manually give prodNum a valid index, but because it's -1 it fails.
Is it possible to launch windows, specifically 8.1, directly into a java based program which would serve as the password entry screen? That is to say, instead of using the standard windows screen, could a java based alternative be used?
I have the source code used on jurassicsystems.com. I would absolutely kill to have a tweaked version of this system act as my password entry screen. It is literally something Ive wanted to have done for ages, and this emulation finally means it may be possible.
I have a list of 100,000 + names and I need to append to that list another 100,000 names. Each name must be unique. Currently I iterate through the entire list to be sure the name does not exist. As you can imagine this is very slow. I am new to Java and I am maintaining a 15+ year old product. Is there a better way to check for an existing name?
View Replies View RelatedGiven the case I have an object which is assigned only once. What is the difference in doing:
public class MyClass {
private MyObj obj = new MyObj("Hello world");
private MyClass(){}
//...
}
and
public class MyClass {
private MyObj obj;
private MyClass(){
obj = new MyObj("Hello world");
}
//...
}
Is there a difference in performance or usability? (Given also the case there are no static calls expected) ....
The term "Local variable" is related to scope. That is a local variable is one which is defined in a certain block of code, and its scope is confined inside that block of code.And a "Member variable" is simple an instance variable.
I read in a discussion forum that when local variables are declared (example code below), their name reservation takes place in memory but they are not automatically initialized to anything. On the other hand, when member variables are declared, they are automatically initialized to null by default.
Java Code: public void myFunction () {
int [] myInt; // A local, member variable (because "static" keyword is not there) declared
} mh_sh_highlight_all('java');
So it seems that they are comparing local variables and member variables. While I think a member variable can also be be local in a block of code, isn't it?
Given a reference variable : Car c1 = new Car();
when we create another variable and set it equal to the first : Car c2 = c1;
we're pointing c2 at the same car object that c1 points to (as opposed to pointing c2 at c1, which in turn points at the car). So if we have code like,
Car c1 = new Car();
Car[] cA = {c1, c1, c1, c1};
are we doing the same? Are we creating four *new* reference variables, each of which points at the same car (again as opposed to pointing them at c1 itself)? I think so, but want to make sure I'm understanding this correctly.
So i have this program that is supposed to execute a command when a button is clicked. I get an error: java.io.IOException: Cannot run program "/Users /brianallison/Documents/Java/RELAP5": error=2, No such file or directory
The actual PATH should be /Users/brianallison/Documents/Java/RELAP5 GUI/issrs/Dist.At least that is where the Java app is and the executable that I am trying to execute when the butotn is clicked. Executable name is relap5.x or relap5.exe depending on the OS.
private void btnRunRelapActionPerformed(java.awt.event.ActionEvent evt) {
String in = " -i " + tfIntdta.getText();
String rst = " - r " + tfRstplt.getText();
String out = " -o " + tfOutdta.getText();
String strip = tfStpdta.getText();
String guistring = "-n gui";
String wd = System.getProperty("user.dir");
String osver = System.getProperty("os.name");
String app = "";
[code].....
I see you can import in 2 ways:
import java.util.*;
or
import java.util.Scanner/Random/etc;
if I used the first one it imports all the librarys within that (directory?). If so would that add to a bigger file size?
I have a directories in UNIX:
/home/t_bmf/Java/HelloWorld/src/helloworld :will contain a .java file
/home/t_bmf/Java/HelloWorld/bin :will contain all .class file
Let say a have a code:
package helloworld;
public class HelloWorld {
public static void main(String[] arg) {
System.out.println("Hello World");
}
}
a command to compile this even outside the directory /home/t_bmf/Java/HelloWorld/src/helloworld
javac -d /home/t_bmf/Java/HelloWorld/bin /home/t_bmf/Java/HelloWorld/src/helloworld/HelloWorld.java
This will generate a directory /home/t_bmf/Java/HelloWorld/bin/helloworld and file inside this is HelloWorld.class
To run this program I must be in directory /home/t_bmf/Java/HelloWorld/bin and using this command:
java helloworld.HelloWorld
Question:
I already how to run the HelloWorld.class, but I must be in helloworld /home/t_bmf/Java/HelloWorld/bin to run it. Is there's a way to run the class even when I am not in directory /home/t_bmf/Java/HelloWorld/bin? Let's say I'm in /home/t_bmf, can I still run the HelloWorld.class?
I am trying to unzip a zip file to a directory but I've tried several different codes and none of them work.The zip structure is like this:
test.zip
New Text Doc.txtNew Folder
New Text Doc.txt
and this is the code I am using
try {
// Open the zip file
ZipFile zipFile = new ZipFile(outputFileName);
Enumeration<?> enu = zipFile.entries();
while (enu.hasMoreElements()) {
ZipEntry zipEntry = (ZipEntry) enu.nextElement();
[code]....
In my program I have to get directory name&address, in this directory is none, one, or more *.txt(maybe not *.txt files) and I have to read info from all of them.
On C++ is very easy to do that with "findnext, find last, findfirst", so how can I do this in Java?