求大神解答一下

错误信息如下

java.lang.StringIndexOutOfBoundsException: String index out of range: -1
    at java.lang.String.substring(String.java:1938)
    at getfile.ui.WebDeployComposite$4.modifyText(WebDeployComposite.java:200)
    at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:179)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1077)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1058)
    at org.eclipse.swt.widgets.Text.wmCommandChild(Text.java:2610)
    at org.eclipse.swt.widgets.Control.WM_COMMAND(Control.java:4669)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:4531)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4972)
    at org.eclipse.swt.internal.win32.OS.CallWindowProcW(Native Method)
    at org.eclipse.swt.internal.win32.OS.CallWindowProc(OS.java:2425)
    at org.eclipse.swt.widgets.Text.callWindowProc(Text.java:255)
    at org.eclipse.swt.widgets.Control.windowProc(Control.java:4623)
    at org.eclipse.swt.widgets.Text.windowProc(Text.java:2254)
    at org.eclipse.swt.widgets.Display.windowProc(Display.java:4972)
    at org.eclipse.swt.internal.win32.OS.SetWindowTextW(Native Method)
    at org.eclipse.swt.internal.win32.OS.SetWindowText(OS.java:3446)
    at org.eclipse.swt.widgets.Text.setText(Text.java:1977)
    at getfile.ui.WebDeployComposite.open(WebDeployComposite.java:206)
    at getfile.ui.WebDeployComposite.<init>(WebDeployComposite.java:38)
    at websrcdeployrc.View.createPartControl(View.java:24)
    at org.eclipse.ui.internal.ViewReference.createPartHelper(ViewReference.java:375)
    at org.eclipse.ui.internal.ViewReference.createPart(ViewReference.java:229)
    at org.eclipse.ui.internal.WorkbenchPartReference.getPart(WorkbenchPartReference.java:595)
    at org.eclipse.ui.internal.Perspective.showView(Perspective.java:2245)
    at org.eclipse.ui.internal.WorkbenchPage.busyShowView(WorkbenchPage.java:1145)
    at org.eclipse.ui.internal.WorkbenchPage$20.run(WorkbenchPage.java:3921)
    at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:70)
    at org.eclipse.ui.internal.WorkbenchPage.showView(WorkbenchPage.java:3918)
    at org.eclipse.ui.handlers.ShowViewHandler.openView(ShowViewHandler.java:162)
    at org.eclipse.ui.handlers.ShowViewHandler.openOther(ShowViewHandler.java:105)
    at org.eclipse.ui.handlers.ShowViewHandler.execute(ShowViewHandler.java:73)
    at org.eclipse.ui.internal.handlers.HandlerProxy.execute(HandlerProxy.java:293)
    at org.eclipse.core.commands.Command.executeWithChecks(Command.java:476)
    at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:508)
    at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:169)
    at org.eclipse.ui.internal.handlers.SlaveHandlerService.executeCommand(SlaveHandlerService.java:241)
    at org.eclipse.ui.internal.ShowViewMenu$3.run(ShowViewMenu.java:187)
    at org.eclipse.jface.action.Action.runWithEvent(Action.java:498)
    at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:584)
    at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:501)
    at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:411)
    at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:84)
    at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1053)
    at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4165)
    at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3754)
    at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2701)
    at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2665)
    at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2499)
    at org.eclipse.ui.internal.Workbench$7.run(Workbench.java:679)
    at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:332)
    at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:668)
    at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149)
    at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:123)
    at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:110)
    at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:79)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:344)
    at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:179)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:622)
    at org.eclipse.equinox.launcher.Main.basicRun(Main.java:577)
    at org.eclipse.equinox.launcher.Main.run(Main.java:1410)
    at org.eclipse.equinox.launcher.Main.main(Main.java:1386)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at com.genuitec.pulse.eclipse.launcher.Main.main(Main.java:110)