Initial import of GenericBinder.

org.springframework.context/src/main/java/org/springframework/model/binder/support/GenericBinder.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright 2004-2009 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.model.binder.support;
+
+import java.util.Map;
+
+import org.springframework.expression.EvaluationContext;
+import org.springframework.expression.EvaluationException;
+import org.springframework.expression.Expression;
+import org.springframework.expression.ExpressionParser;
+import org.springframework.expression.ParseException;
+import org.springframework.expression.spel.standard.SpelExpressionParser;
+import org.springframework.expression.spel.standard.SpelExpressionParserConfiguration;
+import org.springframework.expression.spel.support.StandardEvaluationContext;
+import org.springframework.model.alert.Alert;
+import org.springframework.model.alert.Severity;
+import org.springframework.model.binder.Binder;
+import org.springframework.model.binder.BindingResult;
+import org.springframework.model.binder.BindingResults;
+
+/**
+ * A {@link Binder} implementation that accepts any target object and uses
+ * Spring's Expression Language support to evaluate the keys in the field
+ * value Map.
+ * 
+ * @author Mark Fisher
+ * @since 3.0
+ */
+public class GenericBinder extends AbstractBinder<Object> {
+
+	private final ExpressionParser parser = new SpelExpressionParser(
+			SpelExpressionParserConfiguration.CreateObjectIfAttemptToReferenceNull |
+			SpelExpressionParserConfiguration.GrowListsOnIndexBeyondSize); 
+
+
+	@Override
+	public BindingResults bind(Map<String, ? extends Object> fieldValues, Object model) {
+		StandardEvaluationContext evaluationContext = new StandardEvaluationContext();
+		evaluationContext.setRootObject(model);
+		FieldBinder fieldBinder = new EvaluationContextFieldBinder(this.parser, evaluationContext);
+		return this.getBindTemplate().bind(fieldValues, fieldBinder);
+	}
+
+
+	private static class EvaluationContextFieldBinder implements FieldBinder {
+
+		private final ExpressionParser parser;
+
+		private final EvaluationContext context;
+
+		private EvaluationContextFieldBinder(ExpressionParser parser, EvaluationContext context) {
+			this.parser = parser;
+			this.context = context;
+		}
+
+		@Override
+		public BindingResult bind(String key, Object value) {
+			Alert alert = null;
+			try {
+				Expression e = this.parser.parseExpression(key);
+				e.setValue(this.context, value);
+				alert = new BindSuccessAlert();
+			}
+			catch (ParseException e) {
+				alert = new ParseFailureAlert(e);
+			}
+			catch (EvaluationException e) {
+				alert = new EvaluationFailureAlert(e);
+			}
+			return new AlertBindingResult(key, value, alert);
+		}
+	}
+
+
+	private static class BindSuccessAlert implements Alert {
+
+		public String getCode() {
+			return "bindSuccess";
+		}
+
+		public String getMessage() {
+			return "Binding successful";
+		}
+
+		public Severity getSeverity() {
+			return Severity.INFO;
+		}
+	}
+
+
+	private static class ParseFailureAlert implements Alert {
+
+		private final ParseException exception;
+
+		ParseFailureAlert(ParseException exception) {
+			this.exception = exception;
+		}
+
+		public String getCode() {
+			return "parserFailed";
+		}
+
+		public String getMessage() {
+			return exception.getMessage();
+		}
+
+		public Severity getSeverity() {
+			return Severity.ERROR;
+		}
+	}
+
+
+	private static class EvaluationFailureAlert implements Alert {
+
+		private final EvaluationException exception;
+
+		EvaluationFailureAlert(EvaluationException exception) {
+			this.exception = exception;
+		}
+
+		public String getCode() {
+			return "evaluationFailed";
+		}
+
+		public String getMessage() {
+			return exception.getMessage();
+		}
+
+		public Severity getSeverity() {
+			return Severity.ERROR;
+		}
+	}
+
+}