Add crash catch

app/src/main/java/com/hippo/util/PackageUtils.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2015 Hippo Seven
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.hippo.util;
+
+import android.annotation.SuppressLint;
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.Signature;
+import android.util.Log;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+public final class PackageUtils {
+
+    private static final String TAG = PackageUtils.class.getSimpleName();
+
+    public static String getSignature(Context context, String packageName) {
+        try {
+            @SuppressLint("PackageManagerGetSignatures")
+            PackageInfo pi = context.getPackageManager().getPackageInfo(packageName, PackageManager.GET_SIGNATURES);
+            Signature[] ss = pi.signatures;
+            if (ss != null && ss.length >= 1) {
+                return computeSHA1(ss[0].toByteArray());
+            } else {
+                Log.e(TAG, "Can't find signature in package " + packageName);
+            }
+        } catch (Exception e) {
+            Log.e(TAG, "Can't find package " + packageName, e);
+        }
+        return null;
+    }
+
+    /**
+     * @return looks like A1:43:6B:34... or null
+     */
+    public static String computeSHA1(final byte[] certRaw) {
+        StringBuilder sb = new StringBuilder(59);
+        MessageDigest md;
+        try {
+            md = MessageDigest.getInstance("SHA1");
+            byte[] sha1 = md.digest(certRaw);
+            int length = sha1.length;
+            for (int i = 0; i  < length; i++) {
+                if (i != 0) {
+                    sb.append(':');
+                }
+                byte b = sha1[i];
+                String appendStr = Integer.toString(b & 0xff, 16);
+                if (appendStr.length() == 1) {
+                    sb.append(0);
+                }
+                sb.append(appendStr);
+            }
+
+            return sb.toString().toUpperCase();
+        }
+        catch (NoSuchAlgorithmException ex) {
+            Log.e(TAG, "Can't final Algorithm SHA1", ex);
+            return null;
+        }
+    }
+}