例子1:创建和使用你自己的JAVA类 
创建你自己的JAVA类非常容易。新建一个phptest.java文件,将它放置在你的java.class.path目录下,文件内容如下: 
public class phptest{ 
/** 
* A sample of a class that can work with PHP 
* NB: The whole class must be public to work,  
* and of course the methods you wish to call 
* directly. 
* 
* Also note that from PHP the main method 
* will not be called   
*/ 
public String foo; 
/** 
* Takes a string and returns the result 
* or a msg saying your string was empty 
*/ 
public String test(String str) {    
if(str.equals("")) { 
      str = "Your string was empty. ";    
}    
return str;   
} 
/** 
* whatisfoo() simply returns the value of the variable foo. 
*/   
public String whatisfoo() {    
return "foo is " + foo;   
} 
/** 
* This is called if phptest is run from the command line with 
* something like 
*  java phptest 
* or 
*  java phptest hello there 
*/ 
public static void main(String args[]) { 
phptest p = new phptest(); 
if(args.length == 0) { 
String arg = ""; 
System.out.println(p.test(arg)); 
}else{ 
for (int i=0; i < args.length; i++) { 
String arg = args[i]; 
System.out.println(p.test(arg));   
} 
} 
} 
} 
创建这个文件后,我们要编译好这个文件,在DOS命令行使用javac phptest.java这个命令。 
为了使用PHP测试这个JAVA类,我们创建一个phptest.php文件,内容如下: 
<?php 
 $myj = new Java("phptest"); 
 echo "Test Results are <b>" . $myj->test("Hello World") . "</b>"; 
 $myj->foo = "A String Value"; 
 echo "You have set foo to <b>"   . $myj->foo . "</b><br>n"; 
 echo "My java method reports: <b>" . $myj->whatisfoo() . "</b><br>n"; 
?> 
如果你得到这样的警告信息:java.lang.ClassNotFoundException error ,这就意味着你的phptest.class文件不在你的java.class.path目录下。 
注意的是JAVA是一种强制类型语言,而PHP不是,这样我们在将它们融合时,容易导致错误,于是我们在向JAVA传递变量时,要正确指定好变量的类型。如:$myj->foo = (string) 12345678; or $myj->foo = "12345678"; 
这只是一个很小的例子,你可以创建你自己的JAVA类,并使用PHP很好的调用它!php&java(二)
原文:http://www.jb51.net/article/2022.htm