目录
- DMS
- 1、A "NullPointerException" could be thrown; "sra" is nullable here.
- 2、Cast one of the operands of this multiplication operation to a "long"
- 3、Call "remove()" on "requestContainer".
- 4、Use try-with-resources or close this "FileInputStream" in a "finally" clause.
- 5、Change this condition so that it does not always evaluate to "false"
- 6、Use the "equals" method if value comparison was intended.
- 7、Do something with the "boolean" value returned by "delete".
- 8、Either re-interrupt this method or rethrow the "InterruptedException" that can be caught here.
- DQC
- 1、Use "BigDecimal.valueOf" instead.
- 2、Remove this "break" statement or make it conditional.
- 3、Remove this conditional structure or edit its code blocks so that they're not all the same.
DMS
1、A “NullPointerException” could be thrown; “sra” is nullable here.
这种提示是指可能存在空指针异常，需要增加空值检测。
说明：未做非空校验，可能产生空指针
解决方案：加上非空校验
解决方式：先判断或者先实例化，再访问里面的属性或者成员。
2、Cast one of the operands of this multiplication operation to a “long”
说明：int数运算最终再把结果转为long将有可能产生溢出
解决方案：转换为long型预算
举例：
long bigNum = Integer.MAX_VALUE + 2; // Noncompliant. Yields -2147483647
换为
long bigNum = Integer.MAX_VALUE + 2L;
3、Call “remove()” on “requestContainer”.
说明：防止内存泄露溢出，ThreadLocal字段【requestContainer】应该至少调用一次remove()方法。
// 解决方案：定义删除方法
public void removeRequest() {
requestContainer.remove();
}
4、Use try-with-resources or close this “FileInputStream” in a “finally” clause.
说明：使用try-with-resources或在 “finally” 子句中关闭此 “BufferedOutputStream”。
// 解决方案1：使用try-with-resources
BufferedOutputStream out = null;
try(BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(new File("C://test"))) {
out.write(file.getBytes());
out.flush();
return Result.success("上传成功！", null);
} catch (IOException e) {
return Result.error("上传失败！");
}
// 解决方案2：“finally” 子句中关闭流
BufferedOutputStream out = null;
try {
out = new BufferedOutputStream(new FileOutputStream(new File("C://test"));
out.write(file.getBytes());
out.flush();
return Result.success("上传成功！", null);
} catch (IOException e) {
return Result.error("上传失败！");
} finally {
CloseIoUtils.closeAll(out);
}
5、Change this condition so that it does not always evaluate to “false”
说明：checkInsertParam方法没有返回false的情况一直是true，所以条件判断后一直返回的结果为false。需要改条件判断或者添加方案中异常false情况返回。
6、Use the “equals” method if value comparison was intended.
说明：使用引用等式==或！=，比较java.lang.String或装箱类型（如java.lang.Integer）的两个实例几乎总是一个错误，因为它不是比较实际值，而是比较内存中的位置
解决：将 “==” 换成 equals 比较
7、Do something with the “boolean” value returned by “delete”.
//解决方案:增加false判断
if (!csvFile.delete()) {
log.error("文件删除失败");
}
8、Either re-interrupt this method or rethrow the “InterruptedException” that can be caught here.
//解决方案
try(){
//业务代码...
}catch (InterruptedException e){
//抛出InterruptedException 异常需要重新清除线程的中断状态,添加如下
Thread.currentThread().interrupt();
}
DQC
1、Use “BigDecimal.valueOf” instead.
说明：由于浮点不精确，您不太可能从BigDecimal(double)构造函数中获得预期的值。
//解决方案
BigDecimal.valueOf((double) (Float) r)
2、Remove this “break” statement or make it conditional.
说明：移除break；或者把它放在条件中
3、Remove this conditional structure or edit its code blocks so that they’re not all the same.
说明：写if else的时候，卡条件卡得离散了一点，本身可以合成一个的，结果写成了多级if，增加了程序的复杂度。
解决：去掉if else语句
