StringBuilderInitWithChar
StringBuilder does not have a char constructor; this invokes the int constructor.

Category
Severity
ERROR
Maturity

The problem

StringBuilder does not have a char constructor, so instead this code creates a StringBuilder with initial size equal to the code point of the specified char.

Suppression

Suppress false positives by adding the suppression annotation @SuppressWarnings("StringBuilderInitWithChar") to the enclosing element.


Positive examples

StringBuilderInitWithCharPositiveCases.java

/*
* Copyright 2014 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/


package com.google.errorprone.bugpatterns.testdata;

/** @author lowasser@google.com (Louis Wasserman) */
public class StringBuilderInitWithCharPositiveCases {
{
// BUG: Diagnostic contains: new StringBuilder("a")
new StringBuilder('a');
// BUG: Diagnostic contains: new StringBuilder("\"")
new StringBuilder('"');
char c = 'c';
// BUG: Diagnostic contains: new StringBuilder().append(c)
new StringBuilder(c);
}
}

Negative examples

StringBuilderInitWithCharNegativeCases.java

/*
* Copyright 2014 Google Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/


package com.google.errorprone.bugpatterns.testdata;

/** @author lowasser@google.com (Louis Wasserman) */
public class StringBuilderInitWithCharNegativeCases {
{
new StringBuilder("a");
new StringBuilder(5);
new StringBuilder();
}
}