MLE-19240 Allowing for host to override connection string

Author: rjrudin

marklogic-client-api/src/main/java/com/marklogic/client/impl/DatabaseClientPropertySource.java

@@ -36,6 +36,22 @@ public class DatabaseClientPropertySource {
 
 	static {
 		connectionPropertyHandlers = new LinkedHashMap<>();
+
+		// Connection string is handled first so that certain properties can override it as needed. This is useful
+		// for e.g. specifying a specific host in a cluster while reusing the rest of the connection string.
+		connectionPropertyHandlers.put(PREFIX + "connectionString", (bean, value) -> {
+			if (value instanceof String) {
+				ConnectionString cs = new ConnectionString((String) value, "connection string");
+				bean.setHost(cs.getHost());
+				bean.setPort(cs.getPort());
+				if (cs.getDatabase() != null && cs.getDatabase().trim().length() > 0) {
+					bean.setDatabase(cs.getDatabase());
+				}
+			} else {
+				throw new IllegalArgumentException("Connection string must be of type String");
+			}
+		});
+
 		connectionPropertyHandlers.put(PREFIX + "host", (bean, value) -> {
 			if (value instanceof String) {
 				bean.setHost((String) value);
@@ -59,18 +75,6 @@ public class DatabaseClientPropertySource {
 				throw new IllegalArgumentException("Database must be of type String");
 			}
 		});
-		connectionPropertyHandlers.put(PREFIX + "connectionString", (bean, value) -> {
-			if (value instanceof String) {
-				ConnectionString cs = new ConnectionString((String) value, "connection string");
-				bean.setHost(cs.getHost());
-				bean.setPort(cs.getPort());
-				if (cs.getDatabase() != null && cs.getDatabase().trim().length() > 0) {
-					bean.setDatabase(cs.getDatabase());
-				}
-			} else {
-				throw new IllegalArgumentException("Connection string must be of type String");
-			}
-		});
 		connectionPropertyHandlers.put(PREFIX + "basePath", (bean, value) -> {
 			if (value instanceof String) {
 				bean.setBasePath((String) value);

marklogic-client-api/src/test/java/com/marklogic/client/impl/DatabaseClientPropertySourceTest.java

@@ -196,6 +196,19 @@ void nonNumericPortInConnectionString() {
 		assertEquals("Invalid value for connection string; port must be numeric, but was 'nonNumericPort'", ex.getMessage());
 	}
 
+	@Test
+	void hostTakesPrecedence() {
+		props = new HashMap() {{
+			put(PREFIX + "host", "somehost");
+			put(PREFIX + "connectionString", "user:password@localhost:8000/Documents");
+		}};
+
+		DatabaseClientFactory.Bean bean = buildBean();
+		assertEquals("somehost", bean.getHost(), "This allows a user to use a connection string as a starting " +
+			"point, and then override the host for a direct connection to a particular host in a cluster. This " +
+			"capability is used by our Spark connector to support direct connections to multiple hosts.");
+	}
+
 	private void useConnectionString(String connectionString) {
 		props = new HashMap() {{
 			put(PREFIX + "connectionString", connectionString);