major version 51 is newer than 50, the highest major version supported by this compiler

Question

My current project using jdk1.6.0_32, apache-ant-1.7.1 and CVS for code build.

Now we are migrating to jdk1.7.0_79. So I have modified JAVA_HOME and in the property files that are used for building the code.

After this when I tried to perform the build the code, encountered with the following error.

[javac] warning: java\util\HashMap.class(java\util:HashMap.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\lang\Object.class(java\lang:Object.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\lang\String.class(java\lang:String.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\io\Serializable.class(java\io:Serializable.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\util\ArrayList.class(java\util:ArrayList.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\util\Iterator.class(java\util:Iterator.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\util\Set.class(java\util:Set.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\util\List.class(java\util:List.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\util\Date.class(java\util:Date.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\net\InetAddress.class(java\net:InetAddress.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\sql\Connection.class(java\sql:Connection.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\sql\PreparedStatement.class(java\sql:PreparedStatement.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\sql\ResultSet.class(java\sql:ResultSet.class): major version 51 is newer than 50, the highest major version supported by this compiler.
[javac] It is recommended that the compiler be upgraded.
[javac] warning: java\sql\ResultSetMetaData.class(java\sql:ResultSetMetaData.class): major version 51 is newer than 50, the highest major version supported by this compiler.

[javac] It is recommended that the compiler be upgraded.

Can any one help me in resolving this issue.

Answer 1

We resolved this same issue and set of messages by choosing not to use rt.jar and using other jar files instead.

i.e. we are now using ST-4.0.7.jar ojdbc6.jar mail-1.4.jar commons-io-2.4.jar commons-email-1.3.3.jar