IgnoredStreamReturnValueCheck.java

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import unknownPackage.MyUnknownClass;

class A {
  public void foo() throws Exception {
    FileInputStream is = new FileInputStream("");
    byte[] buffer = new byte[1000];
    long skipValue = 12L;

    is.read(buffer); // Noncompliant [[sc=8;ec=12]] {{Check the return value of the "read" call to see how many bytes were read.}}
    is.skip(skipValue); // Noncompliant
    getInputStream().read(buffer); // Noncompliant
    getInputStream().skip(skipValue); // Noncompliant

    // return values are used
    int i;
    int l;
    i= is.read(buffer); // Compliant
    l = is.skip(skipValue); // Compliant

    // methods not overriding the skip/read from InputStream
    MyInputStream mis = new MyInputStream();
    mis.skip(); // compliant
    mis.skip(true); // compliant
    mis.skip('c'); // compliant
    mis.skip(0L, 0L); // Compliant
    mis.read(0L); // Compliant
    mis.read(buffer, null); // Compliant
    mis.read(buffer, 0, 0); // Compliant

    // same signature but no subtype of InputStream
    MyClass mc = new MyClass();
    mc.read(buffer); // Compliant 
    mc.skip(skipValue); // Complian
    read(buffer); // compliant
    skip(skipValue); // compliant
    
    MyUnknownClass.unknownMethod(); // Compliant
  }

  private InputStream getInputStream() throws Exception {
    return new FileInputStream("");
  }
  
  private int read(byte[] bytes) {
    return 0;
  }
  
  private long skip(long value) {
    return 0L;
  }
}

class MyClass {
  public int read(byte[] bytes) {
    return 0;
  }

  public long skip(long value) {
    return 0L;
  }
}

class MyInputStream extends InputStream {

  @Override
  public int read() {
    return 0;
  }

  public long read(byte[] bytes, Object o) {
    return 0L;
  }

  public int read(long value) {
    return 0;
  }

  public int skip() {
    return 0;
  }

  public boolean skip(boolean value) {
    return value;
  }

  public long skip(char value) {
    return 0L;
  }

  public long skip(long v1, long v2) {
    return 0L;
  }
}