为某个项目加上Java Nature

//直接上代码

IProjectDescription description = project.getDescription();

String[] prevNatures= description.getNatureIds();
String[] newNatures= new String[prevNatures.length + 1];
System.arraycopy(prevNatures, 0, newNatures, 0, prevNatures.length);
newNatures[prevNatures.length]= JavaCore.NATURE_ID;//代表Java Nature
description.setNatureIds(newNatures);
project.setDescription(description, monitor);