Add initial support for CLI structured messages

Added separate writer for outputting structured messages from CLI. Currently, is only able to write to stdout. This can be used in combination with l10n.consoleWriter.consoleOutputType=NONE to achieve parseable output from CLI commands (useful for scripting with a wrapper).

cli/src/main/java/com/box/l10n/mojito/cli/structuredoutput/StructuredWriter.java

@@ -0,0 +1,38 @@
+package com.box.l10n.mojito.cli.structuredoutput;
+
+import org.json.simple.JSONObject;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Writes structured messages to given output.
+ */
+public class StructuredWriter {
+    /**
+     * logger
+     */
+    static Logger logger = LoggerFactory.getLogger(StructuredWriter.class);
+
+    OutputType outputType;
+
+    public StructuredWriter(OutputType outputType) {
+        this.outputType = outputType;
+    }
+
+
+    /**
+     * Write a message to output
+     */
+    public <T extends JSONObject> void write(T message) {
+        String serializedMessage = message.toJSONString();
+        logger.trace(serializedMessage);
+
+        if (outputType == OutputType.STDOUT) {
+            System.out.println(serializedMessage);
+        }
+    }
+
+    public enum OutputType {
+        NONE, STDOUT
+    }
+}

cli/src/main/java/com/box/l10n/mojito/cli/structuredoutput/StructuredWriterConfig.java

@@ -0,0 +1,19 @@
+package com.box.l10n.mojito.cli.structuredoutput;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+
+/**
+ * Configuration for {@link StructuredWriter}.
+ *
+ * @author jaurambault
+ */
+@Configuration
+public class StructuredWriterConfig {
+    @Primary
+    @Bean
+    public StructuredWriter structuredWriter(StructuredWriterConfigurationProperties structuredWriterConfigurationProperties) {
+        return new StructuredWriter(structuredWriterConfigurationProperties.outputType);
+    }
+}

cli/src/main/java/com/box/l10n/mojito/cli/structuredoutput/StructuredWriterConfigurationProperties.java

@@ -0,0 +1,18 @@
+package com.box.l10n.mojito.cli.structuredoutput;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.stereotype.Component;
+
+@Component
+@ConfigurationProperties("l10n.structuredWriter")
+public class StructuredWriterConfigurationProperties {
+    StructuredWriter.OutputType outputType = StructuredWriter.OutputType.NONE;
+
+    public StructuredWriter.OutputType getOutputType() {
+        return outputType;
+    }
+
+    public void setOutputType(StructuredWriter.OutputType outputType) {
+        this.outputType = outputType;
+    }
+}

cli/src/test/java/com/box/l10n/mojito/cli/structuredoutput/StructuredWriterTest.java

@@ -0,0 +1,48 @@
+package com.box.l10n.mojito.cli.structuredoutput;
+
+import org.json.simple.JSONObject;
+import org.junit.Rule;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.boot.test.OutputCapture;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class StructuredWriterTest {
+
+    /**
+     * logger
+     */
+    static Logger logger = LoggerFactory.getLogger(StructuredWriterTest.class);
+
+    @Rule
+    public OutputCapture outputCapture = new OutputCapture();
+
+    @Test
+    public void outputStdout() {
+        StructuredWriter structuredWriter = new StructuredWriter(StructuredWriter.OutputType.STDOUT);
+
+        JSONObject message = new JSONObject();
+        message.put("foo", "bar");
+        message.put("baz", 1);
+
+        structuredWriter.write(message);
+
+        assertTrue(outputCapture.toString().contains(message.toJSONString()));
+    }
+
+    @Test
+    public void disableOutput() {
+        StructuredWriter structuredWriter = new StructuredWriter(StructuredWriter.OutputType.NONE);
+
+        JSONObject message = new JSONObject();
+        message.put("foo", "bar");
+        message.put("baz", 1);
+
+        structuredWriter.write(message);
+
+        assertFalse(outputCapture.toString().contains(message.toJSONString()));
+    }
+}