java通过反射修改静态、私有、final属性

代码上线前，有case覆盖率的要求，DesensUtil 类里的catch分支，没有case能覆盖，开始通过mock的方式，也走不进去，后就想通过反射的方式，把executor属性赋值为null，让报空指针错误。
executor的属性用private static final的方法修饰，通用的反射步骤会报错误:
java.lang.IllegalAccessException: Can not set static final com.alipay.dataseXXX to null。
后看google的文档解决了。

https://stackoverflow.com/questions/3301635/change-private-static-final-field-using-java-reflection

需要反射的类

public class DesensUtil {
    private static final Logger LOGGER = LoggerFactory.getLogger(DesensUtil.class);


    private static final DefaultScanAndDesensExecutor executor     = new DefaultScanAndDesensExecutor();
    private static final DesensConfig                 DESENSCONFIG = new DesensConfigBuilder().appCode(CommonConstants.CLAIMCORE).build();

    /**
     * Scan and desens text string.
     *
     * @param content the content
     * @return the string
     */
    public static String scanAndDesensText(String content) {
        try {
            content = executor.scanAndDesensText(content, DESENSCONFIG);
        } catch (Throwable t) {
            LOGGER.error("scanAndDesensText error,but it is a weakly dependent call");
        }
        return content;
    }
}

测试类:

    @Test
    public void testDesensUtil() throws Exception {
        Class<?> clazz = Class.forName("com.alipay.claimcore.common.util.tools.DesensUtil");
        Field field = clazz.getDeclaredField("executor");
        DesensUtil desensUtil = new DesensUtil();
        setFinalStatic(desensUtil ,field, null);
        desensUtil.scanAndDesensText("");
    }

    private void setFinalStatic(Object obj, Field field, Object newValue) throws Exception {
        field.setAccessible(true);

        Field modifiersField = Field.class.getDeclaredField("modifiers");
        modifiersField.setAccessible(true);
        modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);
        field.set(obj, newValue);
    }