Replace rather than delete existing .settings

Update Eclipse Plugin so that a Gradle refresh will replace contents,
rather than attempting to delete the file and recreate it.

Closes gh-119

Author: philwebb

spring-javaformat-eclipse/io.spring.javaformat.eclipse.tests/src/io/spring/javaformat/eclipse/projectsettings/ProjectSettingsFilesTests.java

@@ -16,6 +16,7 @@
 
 package io.spring.javaformat.eclipse.projectsettings;
 
+import java.io.InputStream;
 import java.util.Collections;
 
 import org.eclipse.core.resources.IFile;
@@ -59,8 +60,7 @@ public void applyToProjectCopiesToDotSettings() throws Exception {
 		given(project.getFile(".settings/foo.prefs")).willReturn(projectFile);
 		given(projectFile.exists()).willReturn(true);
 		files.applyToProject(project, monitor);
-		verify(projectFile).delete(true, monitor);
-		verify(projectFile).create(any(), eq(true), eq(monitor));
+		verify(projectFile).setContents((InputStream) any(), eq(1), eq(monitor));
 	}
 
 }

spring-javaformat-eclipse/io.spring.javaformat.eclipse/plugin.xml

@@ -19,12 +19,6 @@
  <extension
        point="org.eclipse.m2e.core.lifecycleMappingMetadataSource">
  </extension>
- <extension
-       point="org.eclipse.ui.startup">
-    <startup
-          class="io.spring.javaformat.eclipse.Startup">
-    </startup>
- </extension>
  <extension
        point="net.sf.eclipsecs.core.checkstyleAddonProvider">
  </extension>

spring-javaformat-eclipse/io.spring.javaformat.eclipse/src/io/spring/javaformat/eclipse/projectsettings/ProjectSettingsFiles.java

@@ -26,6 +26,7 @@
 
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IProgressMonitor;
 
@@ -65,16 +66,14 @@ public Iterator<ProjectSettingsFile> iterator() {
 	public void applyToProject(IProject project, IProgressMonitor monitor) throws IOException, CoreException {
 		for (ProjectSettingsFile file : this) {
 			IFile destination = project.getFile(".settings/" + file.getName());
-			if (destination.exists()) {
-				try {
-					destination.delete(true, monitor);
+			try (InputStream content = this.projectProperties.getModifiedContent(file)) {
+				if (!destination.exists()) {
+					destination.create(new BufferedInputStream(content), true, monitor);
 				}
-				catch (CoreException ex) {
+				else {
+					destination.setContents(new BufferedInputStream(content), IResource.FORCE, monitor);
 				}
 			}
-			try (InputStream content = this.projectProperties.getModifiedContent(file)) {
-				destination.create(new BufferedInputStream(content), true, monitor);
-			}
 		}
 	}