[SOLR-971] StringBuffer -> StringBuilder for instances that do not require thread-safety

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.4

Environment

Java 6, Tomcat 6

• Assignee: Shalin Shekhar Mangar
• Reporter: Karthik K
• Created: 19/Jan/09 20:01
• Updated: 10/Nov/09 15:51
• Resolved: 05/Feb/09 19:42

Description

A good number of instances of StringBuffer actually do not need thread-safety in the first place since the scope (of the StringBuffer variable) does not escape the method. Replacing them with StringBuilder with better performance.

<code>
$ find . -name *.java | xargs grep -nr "StringBuffer"

./contrib/dataimporthandler/src/main/java/org/apache/solr/handler/dataimport/DataImporter.java:134: StringBuffer sb = new StringBuffer("There are errors in the Schema\n");
./contrib/dataimporthandler/src/main/java/org/apache/solr/handler/dataimport/SqlEntityProcessor.java:132: StringBuffer sb = new StringBuffer(queryString);
./contrib/dataimporthandler/src/main/java/org/apache/solr/handler/dataimport/VariableResolverImpl.java:110: StringBuffer sb = new StringBuffer();
./contrib/javascript/example/reuters/importer/java/org/apache/solr/solrjs/ReutersService.java:238: StringBuffer fileData = new StringBuffer(1000);
./src/test/org/apache/solr/analysis/BaseTokenTestCase.java:37: StringBuffer out = new StringBuffer();
./src/test/org/apache/solr/common/util/IteratorChainTest.java:99: final StringBuffer sb = new StringBuffer();
./src/java/org/apache/solr/schema/DateField.java:295: public StringBuffer format(Date d, StringBuffer toAppendTo,
./src/java/org/apache/solr/analysis/BaseCharFilter.java:66: StringBuffer sb = new StringBuffer();
./src/java/org/apache/solr/util/TestHarness.java:266: StringBuffer buf = new StringBuffer();
./src/java/org/apache/solr/util/TestHarness.java:395: * to a StringBuffer.
./src/java/org/apache/solr/util/TestHarness.java:397: public void appendSimpleDoc(StringBuffer buf, String... fieldsAndValues)
./src/java/org/apache/solr/util/TestHarness.java:408: public static StringBuffer makeSimpleDoc(String... fieldsAndValues) {
./src/java/org/apache/solr/search/ConstantScorePrefixQuery.java:52: StringBuffer buffer = new StringBuffer();
./src/solrj/org/apache/solr/client/solrj/util/ClientUtils.java:179: StringBuffer sb = new StringBuffer();
./src/common/org/apache/solr/common/util/DOMUtil.java:290: StringBuffer sb = new StringBuffer();
./src/common/org/apache/solr/common/util/NamedList.java:201: StringBuffer sb = new StringBuffer();
</code>

Issue Links

• relates to: SOLR-968 NamedList#toString() - StringBuilder as opposed to StringBuffer