ImplicitArrayToString.java

package com.siyeh.igtest.bugs.implicit_array_to_string;

import java.io.PrintWriter;
import java.util.Formatter;




public class ImplicitArrayToString {

    void foo() {
        String[] interfaces = {"java/util/Set", "java/util/List"};
        System.out.println("interfaces: " + interfaces); // triggered
        System.out.printf("interfaces: %s\n", interfaces); // not triggered
        System.out.printf("interfaces: %s, count: %s", interfaces, "2");
        String.format("interfaces: %s\n", interfaces);
        String.format("interfaces: %s, count: %s", interfaces, "2");
      new Formatter().format("interfaces: %s\n", interfaces);
        new PrintWriter(System.out).format("interfaces: %s\n", interfaces);
    }

    private static String wrap3arg2( String format, Object[] formatArguments ) {
        Formatter formatter = new Formatter();
        formatter.format( null, format, formatArguments ); // formatArguments triggers inspection, quickfix changes the semantics
        return formatter.toString();
    }

    private String bar(int[] array) {
        return String.valueOf(array) + array.toString();
    }

    private void noWarnOnCharArrays(char[] cs) {
        System.out.println(cs);
        String.valueOf(cs);
    }

    private void warnOnStringBuilderAppend(int[] is) {
        new StringBuilder().append(is); // calls String.valueOf
    }

    void foo2() {
        System.out.println("new String[10]" + new String[10]);
        final String[] var = new String[10];
        System.out.println("new String[10]" + var);
        System.out.println("new String[10]" + meth());
    }

    private String[] meth() {
        return new String[10];
    }

    public static void main(String[] args) {
        char[] charArray = new char[]{'A', 'B', 'C'};
        System.out.println(charArray); // should not warn
        System.out.println(args); // should indeed warn
    }

    void concatenation(int[] is) {
        String s = "string" + is + "string";
    }
}