Java 是否在GraphicsEnvironment中注销字体?
我最近发现了如何在本地GraphicsEnvironment s.t.注册TTF字体。对于我的用例(SVG到PNG的转码),Apache Batik可能会识别这种字体:Java 是否在GraphicsEnvironment中注销字体?,java,fonts,awt,batik,Java,Fonts,Awt,Batik,我最近发现了如何在本地GraphicsEnvironment s.t.注册TTF字体。对于我的用例(SVG到PNG的转码),Apache Batik可能会识别这种字体: import java.awt.Font; import java.awt.FontFormatException; import java.awt.GraphicsEnvironment; // [...] GraphicsEnvironment lge = GraphicsEnvironment.getLocalGrap
import java.awt.Font;
import java.awt.FontFormatException;
import java.awt.GraphicsEnvironment;
// [...]
GraphicsEnvironment lge = GraphicsEnvironment.getLocalGraphicsEnvironment();
try {
Font font = Font.createFont(Font.TRUETYPE_FONT, fontFile);
lge.registerFont(font);
} catch (FontFormatException e) {
logger.warn(e.getMessage(), e);
} catch (IOException e) {
logger.warn(e.getMessage(), e);
}
然而,我想知道我是否可以取消注册任何预先存在的字体,以保证只有我注册的字体将用于转码
没有GraphicsEnvironment#unregisterFont(…),我如何实现这一点
PS:我不想为GraphicsEnvironment创建子类,因为我不能假设存在任何特定的子类,比如sun.awt.Win32GraphicsEnvironment
编辑:更多信息:
- 随着sun.font.FontManager随着Java7的变化(从类到接口,等等),我不希望使用依赖它的任何解决方法李>
- 我的JVM是Oracle JVM
- 如果没有私有静态变量的反射,这是不可能做到的。。。你确定你需要这样做吗
检查源代码,它可能已经有了你想要的安全性。(这是在调用
GraphicsEnvironment.registerFont
时执行实际工作的方法)
public boolean registerFont(字体){
/*不应使用“null”调用此方法。
*打电话的人有责任确保这一点。
*/
如果(字体==null){
返回false;
}
/*只有在我们开始使用此API时才初始化这些对象*/
已同步(regFamilyKey){
if(createdByFamilyName==null){
createdByFamilyName=新哈希表();
createdByFullName=新哈希表();
}
}
如果(!FontAccess.getFontAccess().isCreatedFont(字体)){
返回false;
}
/*我们希望确保此字体不能覆盖现有字体
*已安装字体。请检查以下条件:
*-族名称不是已安装字体的名称
*-全名不是已安装字体的全名
*-族名称与已安装字体的全名不同
*-全名与已安装字体的族名称不同
*最后两个可能起初看起来很奇怪,但原因是
*(不幸的是)字体构造器不区分这些。
*这种问题的一个极端例子是字体
*姓“Dialog.Plain”和全名“Dialog”。
*这里有一个可能过于严格的限制是
*应用程序希望提供现有族的新成员
*它将被拒绝。但是由于JRE可以执行合成
*在许多情况下,造型是不必要的。
*我们不会对注册字体应用相同的逻辑
*要做到这一点,让我们假设他们有理由。这不会造成问题
*除了他们自己。
*/
HashSet name=getInstalledNames();
语言环境l=getSystemStartupLocale();
字符串familyName=font.getFamily(l.toLowerCase();
字符串fullName=font.getFontName(l).toLowerCase();
if(names.contains(familyName)| | names.contains(fullName)){
返回false;
}
/*检查通过,现在注册字体*/
哈希表家族表;
哈希表fullNameTable;
如果(!maybeMultipAppContext()){
familyTable=createdByFamilyName;
fullNameTable=createdByFullName;
Fontsarregistered=真;
}否则{
AppContext AppContext=AppContext.getAppContext();
家谱=
(哈希表)appContext.get(regFamilyKey);
全名表=
(哈希表)appContext.get(regFullNameKey);
如果(familyTable==null){
familyTable=新哈希表();
fullNameTable=新哈希表();
appContext.put(regFamilyKey,familyTable);
put(regFullNameKey,fullNameTable);
}
FontsarreRegisteredPerAppContext=true;
}
/*创建FontFamily并将字体添加到表中*/
Font2D Font2D=FontUtilities.getFont2D(字体);
int style=font2D.getStyle();
FontFamily=familyTable.get(familyName);
if(family==null){
family=新FontFamily(font.getFamily(l));
familyTable.put(familyName,family);
}
/*如果不使用应用程序上下文,请删除名称缓存项。
*为了适应这样一种情况,代码可能首先注册了一个普通代码
*家庭成员,然后使用它,现在正在注册一个大胆的家庭
*成员,我们需要移除所有家庭成员,以便
*新风格可以被采用,而不是继续合成。
*/
如果(Fontsarreregistered){
removeFromCache(family.getFont(Font.PLAIN));
removeFromCache(family.getFont(Font.BOLD));
removeFromCache(family.getFont(Font.ITALIC));
移除缓存(family.getFont(Font.BOLD | Font.ITALIC));
removeFromCache(fullNameTable.get(fullName));
}
setFont(font2D,样式);
fullNameTable.put(fullName,font2D);
返回true;
}
FontManager API随着Java7的变化而变化,所以,是的,我不想使用反射来处理这个问题。你在哪里找到源代码的?这是OpenJDK吗?我的JVM是Oracle的。@RobertG单击文章顶部的链接。在格雷普编码上
public boolean registerFont(Font font) {
/* This method should not be called with "null".
* It is the caller's responsibility to ensure that.
*/
if (font == null) {
return false;
}
/* Initialise these objects only once we start to use this API */
synchronized (regFamilyKey) {
if (createdByFamilyName == null) {
createdByFamilyName = new Hashtable<String,FontFamily>();
createdByFullName = new Hashtable<String,Font2D>();
}
}
if (! FontAccess.getFontAccess().isCreatedFont(font)) {
return false;
}
/* We want to ensure that this font cannot override existing
* installed fonts. Check these conditions :
* - family name is not that of an installed font
* - full name is not that of an installed font
* - family name is not the same as the full name of an installed font
* - full name is not the same as the family name of an installed font
* The last two of these may initially look odd but the reason is
* that (unfortunately) Font constructors do not distinuguish these.
* An extreme example of such a problem would be a font which has
* family name "Dialog.Plain" and full name of "Dialog".
* The one arguably overly stringent restriction here is that if an
* application wants to supply a new member of an existing family
* It will get rejected. But since the JRE can perform synthetic
* styling in many cases its not necessary.
* We don't apply the same logic to registered fonts. If apps want
* to do this lets assume they have a reason. It won't cause problems
* except for themselves.
*/
HashSet<String> names = getInstalledNames();
Locale l = getSystemStartupLocale();
String familyName = font.getFamily(l).toLowerCase();
String fullName = font.getFontName(l).toLowerCase();
if (names.contains(familyName) || names.contains(fullName)) {
return false;
}
/* Checks passed, now register the font */
Hashtable<String,FontFamily> familyTable;
Hashtable<String,Font2D> fullNameTable;
if (!maybeMultiAppContext()) {
familyTable = createdByFamilyName;
fullNameTable = createdByFullName;
fontsAreRegistered = true;
} else {
AppContext appContext = AppContext.getAppContext();
familyTable =
(Hashtable<String,FontFamily>)appContext.get(regFamilyKey);
fullNameTable =
(Hashtable<String,Font2D>)appContext.get(regFullNameKey);
if (familyTable == null) {
familyTable = new Hashtable<String,FontFamily>();
fullNameTable = new Hashtable<String,Font2D>();
appContext.put(regFamilyKey, familyTable);
appContext.put(regFullNameKey, fullNameTable);
}
fontsAreRegisteredPerAppContext = true;
}
/* Create the FontFamily and add font to the tables */
Font2D font2D = FontUtilities.getFont2D(font);
int style = font2D.getStyle();
FontFamily family = familyTable.get(familyName);
if (family == null) {
family = new FontFamily(font.getFamily(l));
familyTable.put(familyName, family);
}
/* Remove name cache entries if not using app contexts.
* To accommodate a case where code may have registered first a plain
* family member and then used it and is now registering a bold family
* member, we need to remove all members of the family, so that the
* new style can get picked up rather than continuing to synthesise.
*/
if (fontsAreRegistered) {
removeFromCache(family.getFont(Font.PLAIN));
removeFromCache(family.getFont(Font.BOLD));
removeFromCache(family.getFont(Font.ITALIC));
removeFromCache(family.getFont(Font.BOLD|Font.ITALIC));
removeFromCache(fullNameTable.get(fullName));
}
family.setFont(font2D, style);
fullNameTable.put(fullName, font2D);
return true;
}