Do I Need A Java Command Tool For My Mac
The javac command in Java compiles a program from a command prompt. It reads a Java source program from a text file and creates a compiled Java class file. The basic form of the javac command is
For example, to compile a program named HelloWorld.java, use this command:
Normally, the javac command compiles only the file that you specify on the command line, but you can coax javac into compiling more than one file at a time by using any of the following techniques:
If the Java file you specify on the command line contains a reference to another Java class that’s defined by a java file in the same folder, the Java compiler automatically compiles that class, too.
You can list more than one filename in the javac command. The following command compiles three files:
You can use a wildcard to compile all the files in a folder, like this:
If you need to compile a lot of files at the same time but don’t want to use a wildcard (perhaps you want to compile a large number of files but not all the files in a folder), you can create an argument file, which lists the files to compile. In the argument file, you can type as many filenames as you want, using spaces or line breaks to separate them. Here’s an argument file named TestPrograms that lists three files to compile:
You can compile all the programs in this file by using an @character, followed by the name of the argument file on the javac command line, like this:
The javac command has a gaggle of options that you can use to influence how it compiles your programs.
| Option | Description |
|---|---|
| -bootclasspath <path> | Overrides locations of bootstrap class files. (The bootstrap class files are the classes that implement the Java runtime. You will rarely use this option.) |
| -classpath <path> | Specifies where to find user class files. Use this option if your program makes use of class files that you’ve stored in a separate folder. |
| -cp <path> | Same as classpath. |
| -d <directory> | Specifies where to place generated class files. |
| -deprecation | Outputs source locations where deprecated APIs (features that are considered obsolete) are used. Use this option if you want the compiler to warn you whenever you use API methods that have been deprecated. |
| -encoding <encoding> | Specifies character encoding used by source files. |
| -endorseddirs <dirs> | Overrides location of endorsed standards path. |
| -extdirs <dirs> | Overrides locations of installed extensions. |
| -g | Generates all debugging info. |
| -g:{lines,vars,source} | Generates only some debugging info. |
| -g:none | Generates no debugging info. |
| -help | Prints a synopsis of standard options. |
| -J<flag> | Passes <flag> directly to the runtime system. |
| -nowarn | Generates no warnings. |
| -source <release> | Provides source compatibility with specified release. |
| -sourcepath <path> | Specifies where to find input source files. |
| -target <release> | Generates class files for specific virtual machine version. |
| -verbose | Outputs messages about what the compiler is doing. |
| -version | Provides version information. |
| M | Prints a synopsis of nonstandard options. |
A class file is a compiled Java program that can be executed by the java command. The Java compiler reads source files and creates class files.
To use one or more of these options, type the option before or after the source filename. Either of the following commands, for example, compiles the HelloApp.java file with the -verbose and -deprecation options enabled:
Jul 11, 2015 To use the 'java' command-line tool you need to install a JDK. How to install Java JDK on Mac OS X ( with JAVA. How To Install XCode and XCode Command Line Tools on OS X Mountain Lion.
Java Code
The explanation is that JDK is a bit specific and does not contain the library tools.jar.For my development, I need this library and Mac's JDK doesn't provide it. Mac OS X Platform Install FAQ. If you do not develop Java applications, you do not need to worry about this. For more information, see Determining the Default Version of the JDK. Q: How do I clear the Java cache? And will use that for all of the Java related command line tools in /usr/bin. You may need to modify those applications to. The Blog How to: Fix Java Command-Line Tool Pop-Up on Mac OS Truong Nguyen August 29, 2017 How-To After upgrading to a newer version of Mac OS X (Yosemite 10.10 and El Capitan 10.11) or macOS (Sierra 10.12 and High Sierra 10.13), you may end up getting an annoying new pop-up message whenever you start your computer. Mac users must update to the Java 7 Update 13 for Mac OS X. If you are not sure you need Java, try running your PC for a few weeks to see if you can do without it.