how to convert string value toint value?

how to convert string value toint value?

my code does not show date if day is string not numeric, if i replace
value with digit like 2,3,4 is work fine other wise code throws error show
on log cat java.util.IllegalFormatConversionException: d is incompatible
with java.lang.String
String completedate;
String value ;
mYear = mCalendar.get(Calendar.YEAR);
mMonth = mCalendar.get(Calendar.MONTH) + 1;
case R.id.e02:
value=e02.getText().toString();
completedate= String.format("%02d", value) +
String.format("%02d",
mMonth) +mYear;
below is my logcat error
08-15 11:45:11.301: E/AndroidRuntime(1493): FATAL EXCEPTION: main
08-15 11:45:11.301: E/AndroidRuntime(1493):
java.util.IllegalFormatConversionException: d is incompatible with
java.lang.String
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.util.Formatter$Transformer.badArgumentType(Formatter.java:1452)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.util.Formatter$Transformer.transformFromInteger(Formatter.java:1683)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.util.Formatter$Transformer.transform(Formatter.java:1410)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.util.Formatter.doFormat(Formatter.java:1082)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.util.Formatter.format(Formatter.java:994)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.lang.String.format(String.java:2254)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.lang.String.format(String.java:2219)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
com.schoollunchapp.fourthscreen.onClick(fourthscreen.java:687)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
android.view.View.performClick(View.java:2408)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
android.view.View$PerformClick.run(View.java:8816)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
android.os.Handler.handleCallback(Handler.java:587)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
android.os.Handler.dispatchMessage(Handler.java:92)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
android.os.Looper.loop(Looper.java:123)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
android.app.ActivityThread.main(ActivityThread.java:4627)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.lang.reflect.Method.invokeNative(Native Method)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
java.lang.reflect.Method.invoke(Method.java:521)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
08-15 11:45:11.301: E/AndroidRuntime(1493): at
dalvik.system.NativeStart.main(Native Method)