Better error handling in Address.

core/src/main/java/com/google/bitcoin/core/Address.java

@@ -21,6 +21,8 @@ import com.google.bitcoin.params.TestNet3Params;
 
 import javax.annotation.Nullable;
 
+import static com.google.common.base.Preconditions.checkArgument;
+
 /**
  * <p>A Bitcoin address looks like 1MsScoe2fTJoq4ZPdQgqyhgWeoNamYPevy and is derived from an elliptic curve public key
  * plus a set of network parameters. Not to be confused with a {@link PeerAddress} or {@link AddressMessage}
@@ -43,12 +45,11 @@ public class Address extends VersionedChecksummedBytes {
      *
      * <pre>new Address(NetworkParameters.prodNet(), NetworkParameters.getAddressHeader(), Hex.decode("4a22c3c4cbb31e4d03b15550636762bda0baf85a"));</pre>
      */
-    public Address(NetworkParameters params, int version, byte[] hash160) {
+    public Address(NetworkParameters params, int version, byte[] hash160) throws WrongNetworkException {
         super(version, hash160);
+        checkArgument(hash160.length == 20, "Addresses are 160-bit hashes, so you must provide 20 bytes");
         if (!isAcceptableVersion(params, version))
-            throw new RuntimeException("Unrecognized Address version");
+            throw new WrongNetworkException(version, params.getAcceptableAddressCodes());
-        if (hash160.length != 20)  // 160 = 8 * 20
-            throw new RuntimeException("Addresses are 160-bit hashes, so you must provide 20 bytes");
     }
 
     /**
@@ -57,7 +58,8 @@ public class Address extends VersionedChecksummedBytes {
      * <pre>new Address(NetworkParameters.prodNet(), Hex.decode("4a22c3c4cbb31e4d03b15550636762bda0baf85a"));</pre>
      */
     public Address(NetworkParameters params, byte[] hash160) {
-        this(params, params.getAddressHeader(), hash160);
+        super(params.getAddressHeader(), hash160);
+        checkArgument(hash160.length == 20, "Addresses are 160-bit hashes, so you must provide 20 bytes");
     }
 
     /**
@@ -70,7 +72,7 @@ public class Address extends VersionedChecksummedBytes {
      * @throws AddressFormatException if the given address doesn't parse or the checksum is invalid
      * @throws WrongNetworkException if the given address is valid but for a different chain (eg testnet vs prodnet)
      */
-    public Address(@Nullable NetworkParameters params, String address) throws AddressFormatException, WrongNetworkException {
+    public Address(@Nullable NetworkParameters params, String address) throws AddressFormatException {
         super(address);
         if (params != null) {
             if (!isAcceptableVersion(params, version)) {
@@ -89,7 +91,8 @@ public class Address extends VersionedChecksummedBytes {
      * See also https://en.bitcoin.it/wiki/BIP_0013: Address Format for pay-to-script-hash
      */
     public boolean isP2SHAddress() {
-        return this.version == getParameters().p2shHeader;
+        final NetworkParameters parameters = getParameters();
+        return parameters != null && this.version == parameters.p2shHeader;
     }
 
     /**
@@ -100,6 +103,7 @@ public class Address extends VersionedChecksummedBytes {
      *
      * @return a NetworkParameters representing the network the address is intended for, or null if unknown.
      */
+    @Nullable
     public NetworkParameters getParameters() {
         // TODO: There should be a more generic way to get all supported networks.
         NetworkParameters[] networks = { TestNet3Params.get(), MainNetParams.get() };
@@ -114,21 +118,22 @@ public class Address extends VersionedChecksummedBytes {
     /**
      * Given an address, examines the version byte and attempts to find a matching NetworkParameters. If you aren't sure
      * which network the address is intended for (eg, it was provided by a user), you can use this to decide if it is
-     * compatible with the current wallet. You should be able to handle a null response from this method.
+     * compatible with the current wallet.
+     * @return a NetworkParameters or null if the string wasn't of a known version.
      */
+    @Nullable
     public static NetworkParameters getParametersFromAddress(String address) throws AddressFormatException {
         try {
             return new Address(null, address).getParameters();
         } catch (WrongNetworkException e) {
-            // Cannot happen.
+            throw new RuntimeException(e);  // Cannot happen.
-            throw new RuntimeException(e);
         }
     }
 
     /**
      * Check if a given address version is valid given the NetworkParameters.
      */
-    private boolean isAcceptableVersion(NetworkParameters params, int version) {
+    private static boolean isAcceptableVersion(NetworkParameters params, int version) {
         for (int v : params.getAcceptableAddressCodes()) {
             if (version == v) {
                 return true;