Unnecessary call to 'toString()'

Reports calls to toString() that are used in the following cases:

In string concatenations
In the java.lang.StringBuilder#append() or java.lang.StringBuffer#append() methods
In the methods of java.io.PrintWriter or java.io.PrintStream
in the methods org.slf4j.Logger

In these cases, conversion to string will be handled by the underlying library methods, and the explicit call to toString() is not needed.

Example:

System.out.println(this.toString())

After the quick-fix is applied:

System.out.println(this)

Note that without the toString() call, the code semantics might be different: if the expression is null, then the null string will be used instead of throwing a NullPointerException.

Use the Report only when qualifier is known to be not-null option to avoid warnings for the values that could potentially be null.

Inspection options

Option	Type	Default
Report only when qualifier is known to be not-null	Checkbox	true

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Java, 233.SNAPSHOT

Last modified: 13 July 2023