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Java

Java static code analysis

Unique rules to find Bugs, Vulnerabilities, Security Hotspots, and Code Smells in your JAVA code

  • All rules 733
  • Vulnerability60
  • Bug175
  • Security Hotspot40
  • Code Smell458

  • Quick Fix 65
Filtered: 5 rules found
denial-of-service
    Impact
      Clean code attribute
        1. Thread suspensions should not be vulnerable to Denial of Service attacks

           Vulnerability
        2. Custom resources should be closed

           Bug
        3. Zero should not be a possible denominator

           Bug
        4. Regular expressions should not be vulnerable to Denial of Service attacks

           Vulnerability
        5. Resources should be closed

           Bug

        Resources should be closed

        intentionality - complete
        reliability
        Bug
        • cwe
        • leak
        • denial-of-service
        • cert
        • symbolic-execution

        Why is this an issue?

        More Info

        Connections, streams, files, and other classes that implement the Closeable interface or its super-interface, AutoCloseable, needs to be closed after use. Further, that close call must be made in a finally block otherwise an exception could keep the call from being made. Preferably, when class implements AutoCloseable, resource should be created using "try-with-resources" pattern and will be closed automatically.

        Failure to properly close resources will result in a resource leak which could bring first the application and then perhaps the box the application is on to their knees.

        Noncompliant code example

        private void readTheFile() throws IOException {
          Path path = Paths.get(this.fileName);
          BufferedReader reader = Files.newBufferedReader(path, this.charset);
          // ...
          reader.close();  // Noncompliant
          // ...
          Files.lines("input.txt").forEach(System.out::println); // Noncompliant: The stream needs to be closed
        }
        
        private void doSomething() {
          OutputStream stream = null;
          try {
            for (String property : propertyList) {
              stream = new FileOutputStream("myfile.txt");  // Noncompliant
              // ...
            }
          } catch (Exception e) {
            // ...
          } finally {
            stream.close();  // Multiple streams were opened. Only the last is closed.
          }
        }
        

        Compliant solution

        private void readTheFile(String fileName) throws IOException {
            Path path = Paths.get(fileName);
            try (BufferedReader reader = Files.newBufferedReader(path, StandardCharsets.UTF_8)) {
              reader.readLine();
              // ...
            }
            // ..
            try (Stream<String> input = Files.lines("input.txt"))  {
              input.forEach(System.out::println);
            }
        }
        
        private void doSomething() {
          OutputStream stream = null;
          try {
            stream = new FileOutputStream("myfile.txt");
            for (String property : propertyList) {
              // ...
            }
          } catch (Exception e) {
            // ...
          } finally {
            stream.close();
          }
        }
        

        Exceptions

        Instances of the following classes are ignored by this rule because close has no effect:

        • java.io.ByteArrayOutputStream
        • java.io.ByteArrayInputStream
        • java.io.CharArrayReader
        • java.io.CharArrayWriter
        • java.io.StringReader
        • java.io.StringWriter

        Java 7 introduced the try-with-resources statement, which implicitly closes Closeables. All resources opened in a try-with-resources statement are ignored by this rule.

        try (BufferedReader br = new BufferedReader(new FileReader(fileName))) {
          //...
        }
        catch ( ... ) {
          //...
        }
        
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