首先main方法测试的主要原理参见下面的链接

http://www.cnblogs.com/ITEagle/archive/2010/07/10/1774888.html

1、callMainFailure

代码

/**
     * <p>
     * Tests the main method. <code>System.exit</code> is expected.
     * </p>
     *
     * @param args
     *            the arguments.
     */
    private static void callMainFailure(String[] args) {
        try {
            PriceConversionUtility.main(args);

            fail("System.exit is expected.");
        } catch (SecurityException e) {
            // Good
        }
    }

不论main方法正常结束还是异常结束都要System.exit因此这个函数在准确性测试和异常测试中都可以用的到

2、MockSecurityManager

    一个测试的帮助类

代码

import java.security.Permission;

public final class MockSecurityManager extends SecurityManager {
    /**
     * <p>
     * This method throws exception for testing if the status is 1 or 0.
     * </p>
     * 
     * @param status
     *            The exit status code.
     * 
     * @throws SecurityException
     *             Always.
     */
    public void checkExit(int status) {
        super.checkExit(status);
        if (status == 1 || status == 0 || status == -1) {
            throw new SecurityException("Halt for testing.");
        }
    }

    /**
     * <p>
     * This method does nothing.
     * </p>
     * 
     * @param perm
     *            Ignored.
     */
    public void checkPermission(Permission perm) {
    }
}