# HG changeset patch
# User Sascha L. Teichmann <sascha.teichmann@intevation.de>
# Date 1304089844 0
# Node ID fc3cf0ef777e819e23d9630ef1bab05d27e71214
# Parent  dfbb3d50b0bd0f9f104badd9376432f39e839bf0
Added meta data service.


flys-artifacts/trunk@1781 c6561f87-3c4e-4783-a992-168aeb5c3f6f

diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/ChangeLog
--- a/flys-artifacts/ChangeLog	Fri Apr 29 14:39:42 2011 +0000
+++ b/flys-artifacts/ChangeLog	Fri Apr 29 15:10:44 2011 +0000
@@ -1,3 +1,27 @@
+2011-04-29	Sascha L. Teichmann	<sascha.teichmann@intevation.de>
+
+	* src/main/java/de/intevation/flys/artifacts/services/MetaDataService.java:
+	  Forgot to add.
+
+	* src/main/java/de/intevation/flys/artifacts/services/meta/Builder.java:
+	  New. Given a database connection and a XML template it generates
+	  an output with meta data about the database.
+
+	* src/main/java/de/intevation/flys/artifacts/services/meta/CompiledStatement.java:
+	  New. Holds prepared statements optimized to be run in the stack of
+	  contextes.
+
+	* src/main/java/de/intevation/flys/artifacts/services/meta/StackFrames.java:
+	  New. Model to hold a hierarchical scope of variables.
+
+	* src/main/java/de/intevation/flys/artifacts/services/meta/ResultData.java:
+	  New. Stores data set fetched from a sql select to be iterated in
+	  a context.
+
+	* src/main/java/de/intevation/flys/artifacts/model/WstValueTable.java,
+	  src/main/java/de/intevation/flys/collections/FLYSArtifactCollection.java:
+	  Removed superfluous imports.
+
 2011-04-29	Sascha L. Teichmann	<sascha.teichmann@intevation.de>
 
 	* doc/conf/conf.xml: Added meta data service.
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/WstValueTable.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/WstValueTable.java	Fri Apr 29 14:39:42 2011 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/model/WstValueTable.java	Fri Apr 29 15:10:44 2011 +0000
@@ -13,7 +13,6 @@
 import java.util.Comparator;
 import java.util.List;
 import java.util.Collections;
-import java.util.Iterator;
 
 import org.apache.log4j.Logger;
 
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/MetaDataService.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/MetaDataService.java	Fri Apr 29 15:10:44 2011 +0000
@@ -0,0 +1,105 @@
+package de.intevation.flys.artifacts.services;
+
+import java.io.InputStream;
+import java.io.IOException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+import org.w3c.dom.Document;
+
+import org.apache.log4j.Logger;
+
+import de.intevation.artifacts.CallMeta;
+import de.intevation.artifacts.ServiceFactory;
+
+import de.intevation.artifactdatabase.DefaultService;
+
+import de.intevation.artifacts.common.utils.XMLUtils;
+
+import de.intevation.flys.artifacts.services.meta.Builder;
+
+import de.intevation.flys.backend.SessionHolder;
+
+import org.hibernate.Session;
+
+import org.hibernate.jdbc.Work;
+
+public class MetaDataService
+extends      DefaultService
+{
+    private static Logger log = Logger.getLogger(MetaDataService.class);
+
+    public static final String META_DATA_TEMPLATE = "/metadata/template.xml";
+
+    protected Builder builder;
+
+    public MetaDataService() {
+    }
+
+    @Override
+    public Document process(
+        Document data,
+        Object   globalContext,
+        CallMeta callMeta
+    ) {
+        log.debug("MetaDataService.process");
+
+        final Document result = XMLUtils.newDocument();
+
+        if (builder == null) {
+            log.error("MetaDataService is not setup properly.");
+            return result;
+        }
+
+        Session session = SessionHolder.acquire();
+        try {
+            session.doWork(new Work() {
+                @Override
+                public void execute(Connection connection)
+                throws SQLException
+                {
+                    log.debug("MetaDataService.execute");
+                    builder.build(connection, result);
+                }
+            });
+        }
+        finally {
+            session.close();
+            SessionHolder.release();
+        }
+
+        return result;
+    }
+
+    @Override
+    public void setup(ServiceFactory factory, Object globalContext) {
+        log.debug("MetaDataService.setup");
+
+        InputStream in = getClass().getResourceAsStream(META_DATA_TEMPLATE);
+
+        if (in == null) {
+            log.error("cannot get template resource");
+            return;
+        }
+
+        try {
+            Document template = XMLUtils.parseDocument(in);
+            if (template == null) {
+                log.error("cannot parse meta data template");
+            }
+            else {
+                builder = new Builder(template);
+            }
+        }
+        finally {
+            try {
+                in.close();
+            }
+            catch (IOException ioe) {
+                log.error(ioe);
+            }
+        }
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/Builder.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/Builder.java	Fri Apr 29 15:10:44 2011 +0000
@@ -0,0 +1,260 @@
+package de.intevation.flys.artifacts.services.meta;
+
+import java.util.regex.Matcher;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.NodeList;
+import org.w3c.dom.Node;
+import org.w3c.dom.Element;
+
+import java.sql.SQLException;
+import java.sql.Connection;
+
+import de.intevation.artifacts.common.utils.XMLUtils;
+
+import org.apache.log4j.Logger;
+
+public class Builder
+{
+    private static Logger log = Logger.getLogger(Builder.class);
+
+    public static final String DC_NAMESPACE_URI =
+        "http://www.intevation.org/2011/Datacage";
+
+    protected Document   template;
+
+    public class BuildHelper
+    {
+        protected Document    output;
+        protected StackFrames frames;
+        protected Connection  connection;
+        protected Map<String, CompiledStatement> statements;
+
+        public BuildHelper() {
+            frames     = new StackFrames();
+            statements = new HashMap<String, CompiledStatement>();
+        }
+
+        public BuildHelper(Document output, Connection connection) {
+            this();
+            this.output     = output;
+            this.connection = connection;
+        }
+
+        public void build(List<Node> elements) throws SQLException {
+            try {
+                for (Node current: elements) {
+                    build(output, current);
+                }
+            }
+            finally {
+                for (CompiledStatement cs: statements.values()) {
+                    cs.close();
+                }
+                statements.clear();
+            }
+        }
+
+        protected void context(Node parent, Element current)
+        throws SQLException
+        {
+            NodeList elements = current.getElementsByTagNameNS(
+                DC_NAMESPACE_URI, "elements");
+
+            if (elements.getLength() < 1) {
+                log.warn("no elements found -> ignore");
+                return;
+            }
+
+            NodeList subs = elements.item(0).getChildNodes();
+            int S = subs.getLength();
+
+            if (S < 1) {
+                log.warn("elements is empty -> ignore");
+                return;
+            }
+
+            NodeList stmntNode = current.getElementsByTagNameNS(
+                DC_NAMESPACE_URI, "statement");
+
+            if (stmntNode.getLength() < 1) {
+                log.warn("dc:context: too less statements");
+                return;
+            }
+
+            String stmntText = stmntNode.item(0).getTextContent();
+
+            if (stmntText == null) {
+                log.warn("dc:context: no sql statement found");
+            }
+
+            CompiledStatement cs = statements.get(stmntText);
+
+            if (cs == null) {
+                cs = new CompiledStatement(stmntText);
+                statements.put(stmntText, cs);
+            }
+
+            ResultData rd = cs.execute(connection, frames);
+
+            String [] columns = rd.getColumnLabels();
+
+
+            for (Object [] row: rd.getRows()) {
+                frames.enter();
+                try {
+                    frames.put(columns, row);
+                    for (int i = 0; i < S; ++i) {
+                        build(parent, subs.item(i));
+                    }
+                }
+                finally {
+                    frames.leave();
+                }
+            }
+        }
+
+        protected void element(Node parent, Element current)
+        throws SQLException
+        {
+            String attr = expand(current.getAttribute("name"));
+
+            if (log.isDebugEnabled()) {
+                log.debug("dc:element -> '" + attr + "'");
+            }
+
+            if (attr.length() == 0) {
+                log.warn("no name attribute found");
+                return;
+            }
+
+            Element element = output.createElement(attr);
+
+            NodeList children = current.getChildNodes();
+            for (int i = 0, N = children.getLength(); i < N; ++i) {
+                build(element, children.item(i));
+            }
+
+            parent.appendChild(element);
+        }
+
+        protected void text(Node parent, Element current)
+        throws SQLException
+        {
+            log.debug("dc:text");
+            String value = expand(current.getTextContent());
+            parent.appendChild(output.createTextNode(value));
+        }
+
+
+        protected void attribute(Node parent, Element current) {
+
+            if (parent.getNodeType() != Node.ELEMENT_NODE) {
+                log.warn("need element here");
+                return;
+            }
+
+            String name  = expand(current.getAttribute("name"));
+            String value = expand(current.getAttribute("value"));
+
+            Element element = (Element)parent;
+
+            element.setAttribute(name, value);
+        }
+
+        protected String expand(String s) {
+            Matcher m = CompiledStatement.VAR.matcher(s);
+
+            StringBuffer sb = new StringBuffer();
+            while (m.find()) {
+                String key = m.group(1);
+                Object value = frames.get(key);
+                m.appendReplacement(sb, value != null ? value.toString() : "");
+            }
+            m.appendTail(sb);
+            return sb.toString();
+        }
+
+        protected void build(Node parent, Node current) 
+        throws SQLException
+        {
+            String ns = current.getNamespaceURI();
+            if (ns != null && ns.equals(DC_NAMESPACE_URI)) {
+                if (current.getNodeType() != Node.ELEMENT_NODE) {
+                    log.warn("need elements here");
+                }
+                else {
+                    String localName = current.getLocalName();
+                    if ("context".equals(localName)) {
+                        context(parent, (Element)current);
+                    }
+                    else if ("attribute".equals(localName)) {
+                        attribute(parent, (Element)current);
+                    }
+                    else if ("element".equals(localName)) {
+                        element(parent, (Element)current);
+                    }
+                    else if ("text".equals(localName)) {
+                        text(parent, (Element)current);
+                    }
+                    else {
+                        log.warn("unknown '" + localName + "' -> ignore");
+                    }
+                }
+                return;
+            }
+
+            Node copy = output.importNode(current, false);
+
+            NodeList children = current.getChildNodes();
+            for (int i = 0, N = children.getLength(); i < N; ++i) {
+                build(copy, children.item(i));
+            }
+            parent.appendChild(copy);
+        }
+    } // class BuildHelper
+
+
+    public Builder() {
+    }
+
+    public Builder(Document template) {
+        this.template = template;
+    }
+
+    public Document build(Connection connection)
+    throws SQLException
+    {
+        return build(connection, XMLUtils.newDocument());
+    }
+
+    public Document build(Connection connection, Document output)
+    throws SQLException
+    {
+        NodeList roots = template.getElementsByTagNameNS(
+            DC_NAMESPACE_URI, "template");
+
+        BuildHelper helper = new BuildHelper(output, connection);
+
+        List<Node> elements = new ArrayList<Node>();
+
+        for (int i = 0, N = roots.getLength(); i < N; ++i) {
+            NodeList rootChildren = roots.item(i).getChildNodes();
+            for (int j = 0, M = rootChildren.getLength(); j < M; ++j) {
+                Node child = rootChildren.item(j);
+                if (child.getNodeType() == Node.ELEMENT_NODE) {
+                    elements.add(child);
+                }
+            }
+        }
+        helper.build(elements);
+
+        return output;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/CompiledStatement.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/CompiledStatement.java	Fri Apr 29 15:10:44 2011 +0000
@@ -0,0 +1,100 @@
+package de.intevation.flys.artifacts.services.meta;
+
+import java.util.regex.Pattern;
+import java.util.regex.Matcher;
+
+import java.util.List;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.ArrayList;
+
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+import java.sql.Connection;
+import java.sql.ResultSet;
+
+public class CompiledStatement
+{
+    public static final Pattern VAR = Pattern.compile("\\$\\{([a-zA-Z0-9_]+)\\}");
+
+    protected String original;
+    protected String statement;
+
+    protected Map<String, List<Integer>> positions;
+
+    protected PreparedStatement preparedStatement;
+
+    public CompiledStatement() {
+    }
+
+    public CompiledStatement(String original) {
+        this.original = original;
+        positions = new HashMap<String, List<Integer>>();
+        compile();
+    }
+
+    protected void compile() {
+
+        StringBuffer sb = new StringBuffer();
+
+        Matcher m = VAR.matcher(original);
+
+        int index = 1;
+
+        while (m.find()) {
+            String key = m.group(1);
+            List<Integer> indices = positions.get(key);
+            if (indices == null) {
+                indices = new ArrayList<Integer>();
+                positions.put(key, indices);
+            }
+            indices.add(index);
+            m.appendReplacement(sb, "?");
+            ++index;
+        }
+
+        m.appendTail(sb);
+
+        statement = sb.toString();
+    }
+
+    public String getStatement() {
+        return statement;
+    }
+
+    public ResultData execute(Connection connection, StackFrames frames) 
+    throws SQLException
+    {
+        if (preparedStatement == null) {
+            preparedStatement = connection.prepareStatement(statement);
+        }
+
+        for (Map.Entry<String, List<Integer>> entry: positions.entrySet()) {
+            Object value = frames.get(entry.getKey());
+            for (Integer index: entry.getValue()) {
+                preparedStatement.setObject(index, value);
+            }
+        }
+
+        ResultSet result = preparedStatement.executeQuery();
+        try {
+            return new ResultData(preparedStatement.getMetaData())
+                .addAll(result);
+        }
+        finally {
+            result.close();
+        }
+    }
+
+    public void close() {
+        if (preparedStatement != null) {
+            try {
+                preparedStatement.close();
+            }
+            catch (SQLException sqle) {
+            }
+            preparedStatement = null;
+        }
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/ResultData.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/ResultData.java	Fri Apr 29 15:10:44 2011 +0000
@@ -0,0 +1,57 @@
+package de.intevation.flys.artifacts.services.meta;
+
+import java.sql.ResultSetMetaData;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+import java.util.List;
+import java.util.ArrayList;
+
+public class ResultData
+{
+    protected String [] columns;
+
+    protected List<Object []> rows;
+
+    public ResultData() {
+        rows = new ArrayList<Object []>();
+    }
+
+    public ResultData(ResultSetMetaData meta) 
+    throws SQLException
+    {
+        this();
+
+        int N = meta.getColumnCount();
+
+        columns = new String[N];
+
+        for (int i = 1; i <= N; ++i) {
+            columns[i-1] = meta.getColumnLabel(i);
+        }
+    }
+
+    public String [] getColumnLabels() {
+        return columns;
+    }
+
+    public ResultData addAll(ResultSet result) throws SQLException {
+        while (result.next()) {
+            add(result);
+        }
+        return this;
+    }
+
+    public void add(ResultSet result) throws SQLException {
+        Object [] row = new Object[columns.length];
+        for (int i = 0; i < columns.length; ++i) {
+            row[i] = result.getObject(i+1);
+        }
+        rows.add(row);
+    }
+
+    public List<Object []> getRows() {
+        return rows;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/StackFrames.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/services/meta/StackFrames.java	Fri Apr 29 15:10:44 2011 +0000
@@ -0,0 +1,47 @@
+package de.intevation.flys.artifacts.services.meta;
+
+import java.util.Map;
+import java.util.List;
+import java.util.HashMap;
+import java.util.ArrayList;
+
+public class StackFrames
+{
+    protected List<Map<String, Object>> frames;
+
+    public StackFrames() {
+        frames = new ArrayList<Map<String, Object>>();
+    }
+
+    public void enter() {
+        frames.add(new HashMap<String, Object>());
+    }
+
+    public void leave() {
+        frames.remove(frames.size()-1);
+    }
+
+    public void put(String [] keys, Object [] values) {
+        Map<String, Object> top = frames.get(frames.size()-1);
+        for (int i = 0; i < keys.length; ++i) {
+            top.put(keys[i], values[i]);
+        }
+    }
+
+    public Object get(String key) {
+        return get(key, null);
+    }
+
+    public Object get(String key, Object def) {
+
+        for (int i = frames.size()-1; i >= 0; --i) {
+            Map<String, Object> frame = frames.get(i);
+            if (frame.containsKey(key)) {
+                return frame.get(key);
+            }
+        }
+
+        return def;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
diff -r dfbb3d50b0bd -r fc3cf0ef777e flys-artifacts/src/main/java/de/intevation/flys/collections/FLYSArtifactCollection.java
--- a/flys-artifacts/src/main/java/de/intevation/flys/collections/FLYSArtifactCollection.java	Fri Apr 29 14:39:42 2011 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/collections/FLYSArtifactCollection.java	Fri Apr 29 15:10:44 2011 +0000
@@ -4,7 +4,6 @@
 import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.Date;
-import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Vector;