Config processing with lazy error handling

src/main/java/com/github/joschi/jadconfig/JadConfig.java

@@ -2,6 +2,7 @@
 
 import com.github.joschi.jadconfig.converters.NoConverter;
 import com.github.joschi.jadconfig.converters.StringConverter;
+import com.github.joschi.jadconfig.response.ProcessingResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -19,9 +20,7 @@
 import java.util.Objects;
 import java.util.Optional;
 
-import static com.github.joschi.jadconfig.ReflectionUtils.getAllFields;
-import static com.github.joschi.jadconfig.ReflectionUtils.getAllMethods;
-import static com.github.joschi.jadconfig.ReflectionUtils.invokeMethodsWithAnnotation;
+import static com.github.joschi.jadconfig.ReflectionUtils.*;
 
 /**
  * The main class for JadConfig. It's responsible for parsing the configuration bean(s) that contain(s) the annotated
@@ -85,6 +84,8 @@ public JadConfig(Collection<Repository> repositories, Object... configurationBea
      * Processes the configuration provided by the configured {@link Repository} and filling the provided configuration
      * beans.
      *
+     * Stops processing on first encountered exception.
+     *
      * @throws RepositoryException If an error occurred while reading from the configured {@link Repository}
      * @throws ValidationException If any parameter couldn't be successfully validated
      */
@@ -103,53 +104,99 @@ public void process() throws RepositoryException, ValidationException {
         }
     }
 
+    /**
+     * Processes the configuration provided by the configured {@link Repository} and filling the provided configuration
+     * beans.
+     *
+     * Instead of stopping processing on first encountered exception, tries to collect all validation problems and return them in single response,
+     * allowing identifying many problems at once.
+     *
+     * @return Response object, containing encountered problems if processing was not successful.
+     */
+    public ProcessingResponse processFailingLazily() throws RepositoryException {
+
+        ProcessingResponse response = new ProcessingResponse();
+
+        for (Repository repository : repositories) {
+            LOG.debug("Opening repository {}", repository);
+            repository.open();
+        }
+
+        for (Object configurationBean : configurationBeans) {
+            LOG.debug("Processing configuration bean {}", configurationBean);
+
+            response.addOutcome(
+                configurationBean,
+                processClassFieldsFailingLazily(configurationBean, getAllFields(configurationBean.getClass())),
+                invokeValidatorMethodsFailingLazily(configurationBean, getAllMethods(configurationBean.getClass()))
+            );
+        }
+        return response;
+    }
+
 
     private void processClassFields(Object configurationBean, Field[] fields) throws ValidationException {
         for (Field field : fields) {
-            Parameter parameter = field.getAnnotation(Parameter.class);
+            processClassField(configurationBean, field);
+        }
+    }
 
-            if (parameter != null) {
-                LOG.debug("Processing field {}", parameter);
+    private Map<String, Exception> processClassFieldsFailingLazily(Object configurationBean, Field[] fields) {
+        Map<String, Exception> fieldProcessingProblems = new HashMap<>();
+        for (Field field : fields) {
+            try {
+                processClassField(configurationBean, field);
+            } catch (Exception ex) {
+                fieldProcessingProblems.put(field.getAnnotation(Parameter.class).value(), ex);
+            }
+        }
+        return fieldProcessingProblems;
+    }
 
-                Object fieldValue = getFieldValue(field, configurationBean);
+    private void processClassField(Object configurationBean, Field field) throws ValidationException {
+        Parameter parameter = field.getAnnotation(Parameter.class);
 
-                String parameterName = parameter.value();
-                String parameterValue = lookupParameter(parameterName)
-                        .orElseGet(() -> lookupFallbackParameter(parameter));
+        if (parameter != null) {
+            LOG.debug("Processing field {}", parameter);
 
+            Object fieldValue = getFieldValue(field, configurationBean);
 
-                if (parameterValue == null && fieldValue == null && parameter.required()) {
-                    throw new ParameterException("Required parameter \"" + parameterName + "\" not found.");
-                }
+            String parameterName = parameter.value();
+            String parameterValue = lookupParameter(parameterName)
+                    .orElseGet(() -> lookupFallbackParameter(parameter));
 
-                if (parameterValue != null) {
 
-                    if (parameter.trim()) {
-                        LOG.debug("Trimmed parameter value {}", parameterName);
-                        parameterValue = Strings.trim(parameterValue);
-                    }
+            if (parameterValue == null && fieldValue == null && parameter.required()) {
+                throw new ParameterException("Required parameter \"" + parameterName + "\" not found.");
+            }
 
-                    LOG.debug("Converting parameter value {}", parameterName);
-                    try {
-                        fieldValue = convertStringValue(field.getType(), parameter.converter(), parameterValue);
-                    } catch (ParameterException e) {
-                        throw new ParameterException("Couldn't convert value for parameter \"" + parameterName + "\"", e);
-                    }
+            if (parameterValue != null) {
 
-                    LOG.debug("Validating parameter {}", parameterName);
-                    final List<Class<? extends Validator<?>>> validators =
-                            new ArrayList<>(Collections.<Class<? extends Validator<?>>>singleton(parameter.validator()));
-                    validators.addAll(Arrays.asList(parameter.validators()));
-                    validateParameter(validators, parameterName, fieldValue);
+                if (parameter.trim()) {
+                    LOG.debug("Trimmed parameter value {}", parameterName);
+                    parameterValue = Strings.trim(parameterValue);
                 }
 
-                LOG.debug("Setting parameter {} to {}", parameterName, fieldValue);
-
+                LOG.debug("Converting parameter value {}", parameterName);
                 try {
-                    field.set(configurationBean, fieldValue);
-                } catch (Exception e) {
-                    throw new ParameterException("Couldn't set field " + field.getName(), e);
+                    fieldValue = convertStringValue(field.getType(), parameter.converter(), parameterValue);
+                } catch (ParameterException e) {
+                    throw new ParameterException("Couldn't convert value for parameter \"" + parameterName + "\"", e);
                 }
+
+                LOG.debug("Validating parameter {}", parameterName);
+                final List<Class<? extends Validator<?>>> validators =
+                        new ArrayList<>(Collections.<Class<? extends Validator<?>>>singleton(parameter.validator()));
+                validators.addAll(Arrays.asList(parameter.validators()));
+                validateParameter(validators, parameterName, fieldValue);
+            }
+
+            LOG.debug("Setting parameter {} to {}", parameterName, fieldValue);
+
+            try {
+                field.set(configurationBean, fieldValue);
+            } catch (Exception e) {
+                throw new ParameterException("Couldn't set field " + field.getName(), e);
             }
         }
     }
@@ -242,6 +289,27 @@ private void invokeValidatorMethods(Object configurationBean, Method[] methods)
         }
     }
 
+    private Map<String, Exception> invokeValidatorMethodsFailingLazily(Object configurationBean, Method[] methods) {
+        Map<String, Exception> problems = new HashMap<>();
+
+        for (Method method : methods) {
+            if (method.isAnnotationPresent(ValidatorMethod.class)) {
+                try {
+                    method.invoke(configurationBean);
+                } catch (InvocationTargetException invEx) {
+                    if (invEx.getTargetException() instanceof ValidationException) {
+                        problems.put(method.getName(), (ValidationException)invEx.getTargetException());
+                    } else {
+                        problems.put(method.getName(), invEx);
+                    }
+                } catch (Exception ex) {
+                    problems.put(method.getName(), ex);
+                }
+            }
+        }
+        return problems;
+    }
+
     private <T> Class<? extends Converter<T>> findConverter(Class<T> clazz) {
         for (ConverterFactory factory : converterFactories) {
             Class<? extends Converter<T>> result = factory.getConverter(clazz);

src/main/java/com/github/joschi/jadconfig/response/ProcessingOutcome.java

@@ -0,0 +1,35 @@
+package com.github.joschi.jadconfig.response;
+
+import java.util.Map;
+
+public class ProcessingOutcome {
+
+    private final Object configurationBean;
+    private final Map<String, Exception> fieldProcessingProblems;
+    private final Map<String, Exception> validationMethodsProblems;
+
+    public ProcessingOutcome(final Object configurationBean,
+                             final Map<String, Exception> fieldProcessingProblems,
+                             final Map<String, Exception> validationMethodsProblems) {
+        this.configurationBean = configurationBean;
+        this.fieldProcessingProblems = fieldProcessingProblems;
+        this.validationMethodsProblems = validationMethodsProblems;
+    }
+
+    public boolean hasProblems() {
+        return (fieldProcessingProblems != null && !fieldProcessingProblems.isEmpty()) ||
+                (validationMethodsProblems != null && !validationMethodsProblems.isEmpty());
+    }
+
+    public Object getConfigurationBean() {
+        return configurationBean;
+    }
+
+    public Map<String, Exception> getFieldProcessingProblems() {
+        return fieldProcessingProblems;
+    }
+
+    public Map<String, Exception> getValidationMethodsProblems() {
+        return validationMethodsProblems;
+    }
+}

src/main/java/com/github/joschi/jadconfig/response/ProcessingResponse.java

@@ -0,0 +1,29 @@
+package com.github.joschi.jadconfig.response;
+
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Map;
+
+public class ProcessingResponse {
+
+    private List<ProcessingOutcome> outcomes;
+
+    public ProcessingResponse() {
+        this.outcomes = new LinkedList<>();
+    }
+
+    public void addOutcome(final Object configurationBean,
+                    final Map<String, Exception> fieldProcessingProblems,
+                    final Map<String, Exception> validationMethodsProblems) {
+        outcomes.add(new ProcessingOutcome(configurationBean, fieldProcessingProblems, validationMethodsProblems));
+    }
+
+    public List<ProcessingOutcome> getOutcomes() {
+        return outcomes;
+    }
+
+    public boolean isSuccess() {
+        return outcomes.stream().noneMatch(ProcessingOutcome::hasProblems);
+    }
+}
+

src/test/java/com/github/joschi/jadconfig/JadConfigLazyProcessingTest.java

@@ -0,0 +1,47 @@
+package com.github.joschi.jadconfig;
+
+import com.github.joschi.jadconfig.repositories.InMemoryRepository;
+import com.github.joschi.jadconfig.response.ProcessingOutcome;
+import com.github.joschi.jadconfig.response.ProcessingResponse;
+import com.github.joschi.jadconfig.testbeans.ValidatedConfigurationBean;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import static org.junit.Assert.*;
+
+public class JadConfigLazyProcessingTest {
+
+    private JadConfig jadConfig;
+    private Repository repository;
+
+
+    @Test
+    public void testProcess() throws RepositoryException {
+        HashMap<String, String> properties = new HashMap<>();
+        properties.put("test.byte","1");
+        properties.put("test.short","2");
+        properties.put("test.integer","-3");//negative, smaller than test.short
+        properties.put("test.integer.port","70000"); //bigger than allowed port
+        properties.put("test.long","4");
+        properties.put("test.string","Test");
+        repository = new InMemoryRepository(properties);
+        ValidatedConfigurationBean configurationBean = new ValidatedConfigurationBean();
+        jadConfig = new JadConfig(repository, configurationBean);
+
+        ProcessingResponse response = jadConfig.processFailingLazily();
+        assertFalse(response.isSuccess());
+        assertEquals(1, response.getOutcomes().size());
+        ProcessingOutcome processingOutcome = response.getOutcomes().get(0);
+        assertEquals(configurationBean, processingOutcome.getConfigurationBean());
+        Map<String, Exception> fieldProcessingProblems = processingOutcome.getFieldProcessingProblems();
+        assertEquals(2, fieldProcessingProblems.size());
+        assertTrue(fieldProcessingProblems.containsKey("test.integer"));
+        assertTrue(fieldProcessingProblems.containsKey("test.integer.port"));
+
+        Map<String, Exception> validationMethodsProblems = processingOutcome.getValidationMethodsProblems();
+        assertEquals(1, validationMethodsProblems.size());
+        assertTrue(validationMethodsProblems.containsKey("validate"));
+    }
+}