Upgrade Eclipse java compiler

Question

I started using Ant, that ships with Eclipse. It annoys me, that I get hundreds of warnings in the lines of:

[javac] warning: java\\io\\BufferedInputStr

Answer 1

Since my development environment should be based on Java 6 the only thing that helped for this problem was removing Java 7 at all

Answer 2

download and install newer version of JDK.

Windows - > Preference - > Java - > Installed JRE set newer version here

Answer 3

Major version 51 is Java 7 - looks like you're developing against a preview Java 7 API library but compiling with a Java 6 javac. Either make sure ant uses the Java 7 compiler, or use a Java 6 API library to compile against.

Answer 4

One additional thing you probably also need to do is to go under the JRE tab of the Edit Configuration window and select the JRE version.

Answer 5

Thanks, I figured it out.

For those whom it may concern, to make sure Ant uses the Java 7 compiler:

Preferences -> Ant -> Runtime -> Classpath -> Global Entries

Click Add External Jars and put your tools.jar here.

It will look something like C:\Program Files\Java\jdk1.7.0_03\lib

Answer 6

Follow these steps:

1. Download last JDK and install it.
2. Go to C:/Program files/Java and delete the previous JDK.
3. Update your JAVA_HOME and PATH Environment Variables with the new JDK.
4. Open Eclipse and in Windows > Preference > Java > Installed JRE, set newer version here

If there is a broken link with a jar in previous JDK, Eclipse will notify you. I solved in this way the problem with tools.jar ant reference, but it is a general way to find the solution.