推荐回答(2个)
FindBugs是静态分析工具不是错误。
它检查类或者 JAR 文件,将字节码与一组缺陷模式进行对比以发现可能的问题。有了静态分析工具,就可以在不实际运行程序的情况对软件进行分析。不是通过分析类文件的形式或结构来确定程序的意图,而是通常使用 Visitor 模式。
在FindBugs的GUI中,需要先选择待扫描的.class文件(FindBugs其实就是对编译后的class进行扫描,藉以发现一些隐藏的bug。)。如果你拥有这些.class档对应的源文件,可把这些.java文件再选上,这样便可以从稍后得出的报告中快宴模捷的定位到出问题的代码上面。此外,还可以选上工程所使用的library,这样似乎可以帮助FindBugs做一些高阶的检查,藉以发现一些更深层的bug。

扩展资料
findBugs检查的bug类型包括:
1、Malicious code vulnerability:恶意代码
2、Dodgy code:不符合规范的代码
3、Internationalization:国际化相关问慎祥颤题,如错误的字符串转换;
4、Bad practice:坏的实践:常见代码错误,序列化错误,用于静态代码检查时进行缺陷模式匹配;
5、Multithreaded correctness:多线程的正确性:如多线程编程时常见的同步,线程调度问题;
6、Performance:运行时性能问题,如由变量定义,方法调用导致的代码低效问题。
7、Correctness:可宽败能导致错误的代码,如空指针引用等;
8、Experimental:可能受到的恶意攻击,如访问权限修饰符的定义等;
9、Security:安全性
参考资料来源:百度百科-FindBugs
FindBugs常见错误描述和解决方法
(一)
[DLS_DEAD_LOCAL_STORE]
描述: Dead store to 未使用的局部变量
解决方法:局部变量定义后未使用;实例化对象后又重新对该对象赋值锋团
(二) [ST_WRITE_TO_STATIC_FROM_INSTANCE_METHOD]
描述:Write to static field 通过实例方法更新静态属性
常见于常量类,直接通过类名.常量名获取的方式违背了封装的原则,findbugs不提倡使用,而如果将常量改成静态成员变量,又因为spring不支持静态注入导致不能实现,解决方法是非静态的setter调用静态的setter方法给静态成员变量赋值。
解决方法:
常量类F:
class F{
public static String a = “123”;
}
常量a改为静态成员变量,通过F.getA()获取,且由于spring不支持静态注入,改为:
class F{
private static String a;
public static Integer getA() {
return a;
}
public void setA(String a) {
setAValue(a);
}
public static void setAValue(String a) {
F.a = a;
}
}
(三) [BX_UNBOXING_IMMEDIATELY_REBOXED]
描述: Boxed value is unboxed and then immediately reboxed 装箱的值被拆箱,然后立刻重新装箱了
常见的是三目运算时,同时存在基本类型和包装类型。磨基冲
解决方法:
Integer a = null;
//...
a = (a == null)?0:a;
此问题在于a不为null时,会被拆箱,赋值时再装箱。这是自动装箱拆箱的特性,只要运算中有不同类型,当涉及到类型转换时,编译器就会向下转型,再进行运算。修改方法,统一类型:
Integer a = null;
//...
a = (a == null)?Integer.valueOf(0):a;
(四) [SE_BAD_FIELD]
描述: Non-transient non-serializable instance field in serializable class在可序列化的类中存在不能序列化或者不能暂存的数据
解决方法:
方法1:序列化该对象
方法2:当采用struts2框架开瞎歼发,不可避免的此问题会大量出现,因为ActionSupport实现了序列化接口,action继承了此类,而service没序列化,所以在action中引用service对象时提示此错误,最简单的解决方法是将service对象声明成transient,即service不需要序列化
方法3(未验证):To avoid java serialization you need to implement writeObject() and readObject() method in your Class and need to throw NotSerializableException from those method.(action中实现这两个方法?)
private void writeObject(java.io.ObjectOutputStream stream) throws java.io.IOException {
throw new java.io.NotSerializableException( getClass().getName() );
}
private void readObject(java.io.ObjectInputStream stream) throws java.io.IOException, ClassNotFoundException {
throw new java.io.NotSerializableException( getClass().getName() );
}
(五) [NP_LOAD_OF_KNOWN_NULL_VALUE]
描述: Load of known null value加载已知是null的值
解决方法:已知方法参数为null是,直接传递null而不是参数名
(六) [REC_CATCH_EXCEPTION]
描述: Exception is caught when Exception is not thrown 过泛地捕获异常或捕获异常后未做任何处理
解决方法:异常分类捕获(至少要打印出此异常对象)
(七) [NP_NULL_PARAM_DEREF]
描述: Null passed for nonnull parameter 把空值传给了非空的参数
解决方法:增加非空判断
(八) [NP_IMMEDIATE_DEREFERENCE_OF_READLINE]
描述: Immediate dereference of the result of readLine() 立即引用了readLine()的结果
解决方法:判断readLine的结果是否为空
(九) [EI_EXPOSE_REP] 恶意代码漏洞
描述:may expose internal representation by returning getter方法返回引用类型
eclipse自动生成的引用类型(Object、数组、Date等)的getter、setter方法会得到或通过对可变对象的引用操作而暴露代码内部实现,解决方法很多,只要返回的或赋值的对象不是原引用对象即可。
解决方法:
以Date类型为例:
public Date getHappenTime() {
if(happenTime != null){
return (Date) happenTime.clone();
}
return null;
}
(十) [ EI_EXPOSE_REP2] 恶意代码漏洞
描述:may expose internal representation by storing an externally mutable object into setter方法返回引用类型
eclipse自动生成的引用类型(Object、数组、Date等)的getter、setter方法会得到或通过对可变对象的引用操作而暴露代码内部实现,解决方法很多,只要返回的或赋值的对象不是原引用对象即可。
解决方法:
以Date类型为例:
public void setHappenTime(Date happenTime) {
if(happenTime != null){
this.happenTime = (Date) happenTime.clone();
}else{
this.happenTime = null;
}
}
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