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com.izforge.izpack.rules.RulesEngine Maven / Gradle / Ivy
/*
* IzPack - Copyright 2001-2008 Julien Ponge, All Rights Reserved.
*
* http://izpack.org/
* http://izpack.codehaus.org/
*
* Copyright 2007 Dennis Reil
*
* 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 com.izforge.izpack.rules;
import com.izforge.izpack.Pack;
import com.izforge.izpack.installer.InstallData;
import com.izforge.izpack.util.Debug;
import net.n3.nanoxml.XMLElement;
import java.util.*;
/**
* The rules engine class is the central point for checking conditions
*
* @author Dennis Reil, created: 09.11.2006, 13:48:39
*/
public class RulesEngine
{
protected Map panelconditions;
protected Map packconditions;
protected Map optionalpackconditions;
protected XMLElement conditionsspec;
protected static Map conditionsmap = new Hashtable();
protected static InstallData installdata;
private RulesEngine()
{
conditionsmap = new Hashtable();
this.panelconditions = new Hashtable();
this.packconditions = new Hashtable();
this.optionalpackconditions = new Hashtable();
}
/**
* initializes builtin conditions
*/
private void init()
{
createBuiltinOsCondition("IS_WINDOWS", "izpack.windowsinstall");
createBuiltinOsCondition("IS_LINUX", "izpack.linuxinstall");
createBuiltinOsCondition("IS_SUNOS", "izpack.solarisinstall");
createBuiltinOsCondition("IS_MAC", "izpack.macinstall");
createBuiltinOsCondition("IS_SUNOS", "izpack.solarisinstall");
createBuiltinOsCondition("IS_SUNOS_X86", "izpack.solarisinstall.x86");
createBuiltinOsCondition("IS_SUNOS_SPARC", "izpack.solarisinstall.sparc");
if ((installdata != null) && (installdata.allPacks != null))
{
for (Pack pack : installdata.allPacks)
{
if (pack.id != null)
{
// automatically add packselection condition
PackselectionCondition packselcond = new PackselectionCondition();
packselcond.setInstalldata(installdata);
packselcond.id = "izpack.selected." + pack.id;
packselcond.packid = pack.id;
conditionsmap.put(packselcond.id, packselcond);
}
}
}
}
private void createBuiltinOsCondition(String osVersionField, String conditionId)
{
JavaCondition condition = new JavaCondition();
condition.setInstalldata(installdata);
condition.id = conditionId;
condition.classname = "com.izforge.izpack.util.OsVersion";
condition.fieldname = osVersionField;
condition.returnvalue = "true";
condition.returnvaluetype = "boolean";
condition.complete = true;
conditionsmap.put(condition.id, condition);
}
/**
*
*/
public RulesEngine(XMLElement conditionsspecxml, InstallData installdata)
{
this();
this.conditionsspec = conditionsspecxml;
RulesEngine.installdata = installdata;
this.readConditions();
init();
}
public RulesEngine(Map rules, InstallData installdata)
{
this();
RulesEngine.installdata = installdata;
conditionsmap = rules;
Iterator keyiter = conditionsmap.keySet().iterator();
while (keyiter.hasNext())
{
String key = (String) keyiter.next();
Condition condition = (Condition) conditionsmap.get(key);
condition.setInstalldata(installdata);
}
init();
}
/**
* Returns the current known condition ids.
*
* @return
*/
public String[] getKnownConditionIds()
{
String[] conditionids = (String[]) this.conditionsmap.keySet().toArray(new String[this.conditionsmap.size()]);
Arrays.sort(conditionids);
return conditionids;
}
/**
* Checks if an attribute for an xmlelement is set.
*
* @param val value of attribute to check
* @param attribute the attribute which is checked
* @param element the element
* @return true value was set false no value was set
*/
protected boolean checkAttribute(String val, String attribute, String element)
{
if ((val != null) && (val.length() > 0))
{
return true;
}
else
{
Debug.trace("Element " + element + " has to specify an attribute " + attribute);
return false;
}
}
public static Condition analyzeCondition(XMLElement condition)
{
String condid = condition.getAttribute("id");
String condtype = condition.getAttribute("type");
Condition result = null;
if (condtype != null)
{
String conditionclassname = "";
if (condtype.indexOf('.') > -1)
{
conditionclassname = condtype;
}
else
{
String conditiontype = condtype.toLowerCase();
conditionclassname = "com.izforge.izpack.rules."
+ conditiontype.substring(0, 1).toUpperCase()
+ conditiontype.substring(1, conditiontype.length());
conditionclassname += "Condition";
}
//ClassLoader loader = ClassLoader.getSystemClassLoader();
ClassLoader loader = RulesEngine.class.getClassLoader();
try
{
Class conditionclass = (Class) loader.loadClass(conditionclassname);
result = conditionclass.newInstance();
result.readFromXML(condition);
result.setId(condid);
result.setInstalldata(RulesEngine.installdata);
}
catch (ClassNotFoundException e)
{
Debug.trace(conditionclassname + " not found.");
}
catch (InstantiationException e)
{
Debug.trace(conditionclassname + " couldn't be instantiated.");
}
catch (IllegalAccessException e)
{
Debug.trace("Illegal access to " + conditionclassname);
}
}
return result;
}
/**
* Read the spec for the conditions
*/
protected void readConditions()
{
if (this.conditionsspec == null)
{
Debug.trace("No specification for conditions found.");
return;
}
try
{
if (this.conditionsspec.hasChildren())
{
// read in the condition specs
Vector childs = this.conditionsspec.getChildrenNamed("condition");
for (XMLElement condition : childs)
{
Condition cond = analyzeCondition(condition);
if (cond != null)
{
// this.conditionslist.add(cond);
String condid = cond.getId();
cond.setInstalldata(RulesEngine.installdata);
if ((condid != null) && !("UNKNOWN".equals(condid)))
{
conditionsmap.put(condid, cond);
}
}
}
Vector panelconditionels = this.conditionsspec.getChildrenNamed("panelcondition");
for (XMLElement panelel : panelconditionels)
{
String panelid = panelel.getAttribute("panelid");
String conditionid = panelel.getAttribute("conditionid");
this.panelconditions.put(panelid, conditionid);
}
Vector packconditionels = this.conditionsspec.getChildrenNamed("packcondition");
for (XMLElement panelel : packconditionels)
{
String panelid = panelel.getAttribute("packid");
String conditionid = panelel.getAttribute("conditionid");
this.packconditions.put(panelid, conditionid);
// optional install allowed, if condition is not met?
String optional = panelel.getAttribute("optional");
if (optional != null)
{
boolean optionalinstall = Boolean.valueOf(optional);
if (optionalinstall)
{
// optional installation is allowed
this.optionalpackconditions.put(panelid, conditionid);
}
}
}
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
public static Condition getCondition(String id)
{
Condition result = (Condition) conditionsmap.get(id);
if (result == null)
{
result = getConditionByExpr(new StringBuffer(id));
}
return result;
}
protected static Condition getConditionByExpr(StringBuffer conditionexpr)
{
Condition result = null;
int index = 0;
while (index < conditionexpr.length())
{
char currentchar = conditionexpr.charAt(index);
switch (currentchar)
{
case '+':
// and-condition
Condition op1 = (Condition) conditionsmap.get(conditionexpr.substring(0, index));
conditionexpr.delete(0, index + 1);
result = new AndCondition(op1, getConditionByExpr(conditionexpr));
result.setInstalldata(RulesEngine.installdata);
break;
case '|':
// or-condition
op1 = (Condition) conditionsmap.get(conditionexpr.substring(0, index));
conditionexpr.delete(0, index + 1);
result = new OrCondition(op1, getConditionByExpr(conditionexpr));
result.setInstalldata(RulesEngine.installdata);
break;
case '\\':
// xor-condition
op1 = (Condition) conditionsmap.get(conditionexpr.substring(0, index));
conditionexpr.delete(0, index + 1);
result = new XOrCondition(op1, getConditionByExpr(conditionexpr));
result.setInstalldata(RulesEngine.installdata);
break;
case '!':
// not-condition
if (index > 0)
{
Debug.trace("error: ! operator only allowed at position 0");
}
else
{
// delete not symbol
conditionexpr.deleteCharAt(index);
result = new NotCondition(getConditionByExpr(conditionexpr));
result.setInstalldata(RulesEngine.installdata);
}
break;
default:
// do nothing
}
index++;
}
if (conditionexpr.length() > 0)
{
result = (Condition) conditionsmap.get(conditionexpr.toString());
if (result != null)
{
result.setInstalldata(RulesEngine.installdata);
conditionexpr.delete(0, conditionexpr.length());
}
}
return result;
}
public boolean isConditionTrue(String id, Properties variables)
{
Condition cond = getCondition(id);
if (cond == null)
{
Debug.trace("Condition (" + id + ") not found.");
return true;
}
else
{
Debug.trace("Checking condition");
try
{
return cond.isTrue();
}
catch (NullPointerException npe)
{
Debug.error("Nullpointerexception checking condition: " + id);
return false;
}
}
}
public boolean isConditionTrue(Condition cond, Properties variables)
{
if (cond == null)
{
Debug.trace("Condition not found.");
return true;
}
else
{
Debug.trace("Checking condition");
return cond.isTrue();
}
}
public boolean isConditionTrue(String id)
{
Condition cond = RulesEngine.getCondition(id);
if (cond != null)
{
return this.isConditionTrue(cond);
}
else
{
return false;
}
}
public boolean isConditionTrue(Condition cond)
{
return cond.isTrue();
}
/**
* Can a panel be shown?
*
* @param panelid - id of the panel, which should be shown
* @param variables - the variables
* @return true - there is no condition or condition is met false - there is a condition and the
* condition was not met
*/
public boolean canShowPanel(String panelid, Properties variables)
{
Debug.trace("can show panel with id " + panelid + " ?");
if (!this.panelconditions.containsKey(panelid))
{
Debug.trace("no condition, show panel");
return true;
}
Debug.trace("there is a condition");
Condition condition = getCondition(this.panelconditions.get(panelid));
if (condition != null)
{
return condition.isTrue();
}
return false;
}
/**
* Is the installation of a pack possible?
*
* @param packid
* @param variables
* @return true - there is no condition or condition is met false - there is a condition and the
* condition was not met
*/
public boolean canInstallPack(String packid, Properties variables)
{
if (packid == null)
{
return true;
}
Debug.trace("can install pack with id " + packid + "?");
if (!this.packconditions.containsKey(packid))
{
Debug.trace("no condition, can install pack");
return true;
}
Debug.trace("there is a condition");
Condition condition = getCondition(this.packconditions.get(packid));
if (condition != null)
{
return condition.isTrue();
}
return false;
}
/**
* Is an optional installation of a pack possible if the condition is not met?
*
* @param packid
* @param variables
* @return
*/
public boolean canInstallPackOptional(String packid, Properties variables)
{
Debug.trace("can install pack optional with id " + packid + "?");
if (!this.optionalpackconditions.containsKey(packid))
{
Debug.trace("not in optionalpackconditions.");
return false;
}
else
{
Debug.trace("optional install possible");
return true;
}
}
}
