String constants improvement.

src/main/java/com/amazonaws/services/dynamodb/sessionmanager/DynamoDBSessionManager.java

@@ -23,6 +23,7 @@
 import com.amazonaws.internal.StaticCredentialsProvider;
 import com.amazonaws.regions.RegionUtils;
 import com.amazonaws.services.dynamodb.sessionmanager.converters.SessionConverter;
+import com.amazonaws.services.dynamodb.sessionmanager.util.Constants;
 import com.amazonaws.services.dynamodb.sessionmanager.util.DynamoUtils;
 import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
 import com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapper;
@@ -154,7 +155,7 @@ private AWSCredentialsProvider initCredentials() {
         if (credentialsExistInContextConfig()) {
             // Fail fast if credentials aren't valid as user has likely made a configuration mistake
             if (credentialsInContextConfigAreValid()) {
-                throw new AmazonClientException("Incomplete AWS security credentials specified in context.xml.");
+                throw new AmazonClientException(Constants.INCOMPLETE_AWS_IN_CONTEXT);
             }
             logger.debug("Using AWS access key ID and secret key from context.xml");
             return new StaticCredentialsProvider(new BasicAWSCredentials(accessKey, secretKey));
@@ -168,20 +169,15 @@ private AWSCredentialsProvider initCredentials() {
                 logger.debug("Using AWS credentials from file: " + credentialsFile);
                 return new StaticCredentialsProvider(credentials);
             } catch (Exception e) {
-                throw new AmazonClientException(
-                        "Unable to read AWS security credentials from file specified in context.xml: "
-                                + credentialsFile,
-                        e);
+                throw new AmazonClientException(Constants.UNABLE_READ_AWS_SECURUTY_CREDENTIALS_IN_CONTEXT + credentialsFile, e);
             }
         }
 
         // Fall back to the default credentials chain provider if credentials weren't explicitly set
         AWSCredentialsProvider defaultChainProvider = new DefaultAWSCredentialsProviderChain();
         if (defaultChainProvider.getCredentials() == null) {
             logger.debug("Loading security credentials from default credentials provider chain.");
-            throw new AmazonClientException("Unable to find AWS security credentials.  "
-                    + "Searched JVM system properties, OS env vars, and EC2 instance roles.  "
-                    + "Specify credentials in Tomcat's context.xml file or put them in one of the places mentioned above.");
+            throw new AmazonClientException(Constants.UNABLE_FIND_AWS_SECURUTY_CREDENTIALS);
         }
         logger.debug("Using default AWS credentials provider chain to load credentials");
         return defaultChainProvider;
@@ -211,8 +207,7 @@ private ClientConfiguration initClientConfiguration() {
         if (proxyHost != null || proxyPort != null) {
             logger.debug("Reading proxy settings from context.xml");
             if (proxyHost == null || proxyPort == null) {
-                throw new AmazonClientException("Incomplete proxy settings specified in context.xml."
-                        + " Both proxy hot and proxy port needs to be specified");
+                throw new AmazonClientException(Constants.INCOMPLETE_PROXY_SETTINGS_IN_CONTEXT);
             }
             logger.debug("Using proxy host and port from context.xml");
             clientConfiguration.withProxyHost(proxyHost).withProxyPort(proxyPort);

src/main/java/com/amazonaws/services/dynamodb/sessionmanager/util/Constants.java

@@ -0,0 +1,8 @@
+package com.amazonaws.services.dynamodb.sessionmanager.util;
+
+public class Constants {
+	public static final String INCOMPLETE_AWS_IN_CONTEXT = "Incomplete AWS security credentials specified in context.xml.";
+	public static final String UNABLE_READ_AWS_SECURUTY_CREDENTIALS_IN_CONTEXT= "Unable to read AWS security credentials from file specified in context.xml: ";
+	public static final String UNABLE_FIND_AWS_SECURUTY_CREDENTIALS = "Unable to find AWS security credentials. Searched JVM system properties, OS env vars, and EC2 instance roles. Specify credentials in Tomcat's context.xml file or put them in one of the places mentioned above.";
+	public static final String INCOMPLETE_PROXY_SETTINGS_IN_CONTEXT = "Incomplete proxy settings specified in context.xml. Both proxy hot and proxy port needs to be specified";
+}