我如何开始使用JFreeChart？ [英] How do I get started with JFreeChart?

问题描述

我之前从未使用过任何第三方库。我下载 jfreechart-1.0.14.tar.gz 后该怎么办？

I've never used any third party library before. What should I do after I downloaded jfreechart-1.0.14.tar.gz?

我不知道如果我正确地做这些事情：

1.把 jcommon-1.0.17.jar 和 jfreechart-1.0 .14.jar 与我的源代码位于同一目录。

2.在源代码中导入所需的类（例如 import org.jfree.util .Rotation; ）

I don't know if I'm doing these things right:
1. Put the jcommon-1.0.17.jar and jfreechart-1.0.14.jar at the same directory as my source code.
2. Import needed class in the source code (e.g. import org.jfree.util.Rotation;)

许多文章都告诉你如何在IDE中做到这一点。但是我没有使用IDE，而是用vim编写代码并自己编译。所以，假设我没有做任何错误，我应该如何使用 javac 编译源代码并使用 java ？

Many articles tell you how to do this in IDEs. But instead of IDEs, I'm writing codes with vim and compile by myself. So, assume I didn't do any thing wrong, how should I compile the source code with javac and run the code with java?

编辑：

这是我的文件布局：

./src

| - test.java

./lib

| - jcommon-1.0.17.jar

| - jfreechart-1.0.14.jar

Here's my file layout:
./src
| - test.java
./lib
| - jcommon-1.0.17.jar
| - jfreechart-1.0.14.jar

我编译


javac -cplib / *-d classes / src / test.java

然后运行

java -cp类：lib / jcommon-1.0.17.jar ：jfreechart-1.0.14.jar test

但是，发生了一些错误：

线程main中的异常java.lang.NoClassDefFoundError：org / jfree / data / general / PieDataset

However, some error occurs:
Exception in thread "main" java.lang.NoClassDefFoundError: org/jfree/data/general/PieDataset

如何解决此问题？

Exception in thread "main" java.lang.NoClassDefFoundError: org/jfree/data/general/PieDataset  
at java.lang.Class.getDeclaredMethods0(Native Method)  
at java.lang.Class.privateGetDeclaredMethods(Unknown Source)  
at java.lang.Class.getMethod0(Unknown Source)  
at java.lang.Class.getMethod(Unknown Source)  
at sun.launcher.LauncherHelper.getMainMethod(Unknown Source)  
at sun.launcher.LauncherHelper.checkAndLoadMain(Unknown Source)  
Caused by: java.lang.ClassNotFoundException: org.jfree.data.general.PieDataset  
at java.net.URLClassLoader$1.run(Unknown Source)  
at java.net.URLClassLoader$1.run(Unknown Source)  
at java.security.AccessController.doPrivileged(Native Method)  
at java.net.URLClassLoader.findClass(Unknown Source)  
at java.lang.ClassLoader.loadClass(Unknown Source)  
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)  
at java.lang.ClassLoader.loadClass(Unknown Source)  
... 6 more

推荐答案

库不应与源代码位于同一位置。如果您不想使用像Gradle那样的构建工具，它会处理您的库依赖项，那么我建议使用以下布局：

The libraries shouldn't be at the same place as the source code. If you don't want to use a build tool like Gradle yet, which would handle your library dependencies, then I suggest using the following layout:

project
    src
        .java files here, organized in a folder tree matching the package tree
    classes
        compiled .class files here
    lib
        .jar files here

要编译，请进入项目目录并执行以下命令：

To compile, go in the project directory and execute the following command:

javac -cp lib/jfreechart-1.0.14.jar:lib/jcommon-1.0.17.jar -d classes src/com/foo/bar/MyClass.java src/com/foo/bar/MyOtherClass.java

运行你的应用程序，执行以下命令：

To run your app, execute the following command:

java -cp classes:lib/jfreechart-1.0.14.jar:lib/jcommon-1.0.17.jar com.foo.bar.MyClass

这篇关于我如何开始使用JFreeChart？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！