c++ 编写xml操作类

        今天花点时间写了个xml的操作类，模拟树来实现结点的数据结构的。废话不说，看代码：

#include <iostream> #include <string> #include <vector> using namespace std; class xml; class nodecollect; class node{ public: string getattr(string); void setattr(string,string); void appned(node *); void removechild(int); void insert(int,node*); node *getnext(); node *getparent(); node *getprevious(); node *getchild(int); nodecollect *getnodebyname(string); int getcount(); string gettag(); string gettype(); private: friend class xml; int count; node *child; node *next; node *parent; string data; string tag; string type; }; class nodecollect{ public: nodecollect(); int getcount(); node *item(int); void push(node*); private: int count; vector<node*> v; }; class xml{ public: xml(); ~xml(); void loadstring(string); void scan(string); void out(string&,node *); node *getchild(int); nodecollect *getnodebyname(string); int getcount(); node *createnode(string); node *createtextnode(string); private: node* root; int count; void output(node *,string&); }; xml::xml(){ root=0; count=0; } xml::~xml(){ } void xml::loadstring(string s){ scan(s); } void xml::scan(string s){ int i=0; node *p=0; while(1){ if(i==s.length()){ break; } if(s[i]=='<' && s[i+1]!='/'){ node *n=new node; count++; n->next=0; n->child=0; n->count=0; n->type="node"; if(p){ n->parent=p; n->parent->count++; node *n1=p->child; if(n1){ while(n1->next){ n1=n1->next; } n1->next=n; }else{ p->child=n; } }else{ n->parent=0; if(!root){ root=n; }else{ node* n1=root; while(n1->next){ n1=n1->next; } n1->next=n; } } i++; while(s[i]!='>'){ if(s[i]!='/') n->data.append(1,s[i]); i++; } int index=n->data.find(' '); n->tag=n->data.substr(0,index!=-1?index:n->data.find('>')); if(s[i-1]!='/' && s[i-1]!='?' && s[i-1]!=']'){ p=n; } }else if(s[i]=='<' && s[i+1]=='/'){ if(p->parent){ p=p->parent; }else{ p=0; } while(s[i]!='>'){ char t=s[i]; i++; } }else if(s[i]!='/t' && s[i]!=' ' && s[i]!='/r' && s[i]!='/n'){ node *n=new node; count++; n->next=0; n->child=0; n->count=0; n->parent=p; n->type="text"; n->parent->count++; node *n1=p->child; if(n1){ while(n1->next){ n1=n1->next; } n1->next=n; }else{ p->child=n; } while(s[i]!='<'){ n->data.append(1,s[i]); i++; } for(int i1=n->data.length()-1;i1>=0;i1--){ if(n->data[i1]!='/t' && n->data[i1]!=' '){ break; }else{ n->data[i1]=0; } } continue; } i++; } } void xml::out(string& s,node *n=0){ if(!n) output(root->next,s); else output(n,s); } void xml::output(node * n,string& s){ node *n1=n; int tab=0; if(n1->child || n1==root){ s=s+"<"+n1->data+">"+"/r/n"; }else{ s=s+"<"+n1->data+"/>"+"/r/n"; } while(1){ if(n1->child){ n1=n1->child; tab++; for(int i1=0;i1<tab;i1++){ s=s+"/t"; } if(n1->type=="text"){ s=s+n1->data+"/r/n"; }else{ if(n1->count>0){ s=s+"<"+n1->data+">"+"/r/n"; }else{ s=s+"<"+n1->data+"/>"+"/r/n"; } } }else if(n1->next && n1!=n){ if(n1->count>0){ for(int i2=0;i2<tab;i2++){ s=s+"/t"; } s=s+"</"+n1->tag+">"+"/r/n"; } n1=n1->next; for(int i1=0;i1<tab;i1++){ s=s+"/t"; } if(n1->type=="text"){ s=s+n1->data+"/r/n"; }else{ if(n1->count>0){ s=s+"<"+n1->data+">"+"/r/n"; }else{ s=s+"<"+n1->data+"/>"+"/r/n"; } } }else{ //s=s+"</"+n1->tag+">"+"/r/n"; node *n2=n1->parent,*n3=0; if(n2 && n1!=n){ while(n2->next==0){ tab--; for(int i1=0;i1<tab;i1++){ s=s+"/t"; } s=s+"</"+n2->tag+">"+"/r/n"; n3=n2; n2=n2->parent; if(n2==0){ tab--; for(int i1=0;i1<tab;i1++){ s=s+"/t"; } // s=s+"</"+n3->tag+">"+"/r/n"; goto a; } } tab--; for(int i1=0;i1<tab;i1++){ s=s+"/t"; } s=s+"</"+n2->tag+">"+"/r/n"; n1=n2->next; for(int i2=0;i2<tab;i2++){ s=s+"/t"; } if(n1->count>0){ s=s+"<"+n1->data+">"+"/r/n"; }else{ s=s+"<"+n1->data+"/>"+"/r/n"; } }else{ // s=s+"</"+n1->tag+">"+"/r/n"; a: break; } } } } int xml::getcount(){ return count; } node *xml::getchild(int i){ int i1=0; node *n=root; while(i1!=i){ if(n->child){ n=n->child; }else{ if(n->next){ n=n->next; }else{ n=n->parent; continue; } } i1++; } return n; } nodecollect *xml::getnodebyname(string s){ node *n1=root; nodecollect *nc=new nodecollect; if(n1->tag==s){ nc->push(n1); } while(1){ if(n1->child){ n1=n1->child; if(n1->tag==s){ nc->push(n1); } }else if(n1->next){ n1=n1->next; if(n1->tag==s){ nc->push(n1); } }else{ //cout<<"</"<<n1->tag<<">"<<endl; node *n2=n1->parent,*n3=0; if(n2){ while(n2->next==0){ n3=n2; n2=n2->parent; if(n2==0){ goto a; } } n1=n2->next; if(n1->tag==s){ nc->push(n1); } }else{ // cout<<"</"<<n1->tag<<">"<<endl; a: break; } } } return nc; } node *xml::createnode(string s){ node *n=new node; n->child=0; n->next=0; n->parent=0; n->type="node"; n->tag=s; n->data=s; return n; } node *xml::createtextnode(string s){ node *n=new node; n->child=0; n->next=0; n->parent=0; n->type="text"; n->data=s; return n; } nodecollect::nodecollect(){ count=0; } int nodecollect::getcount(){ return count; } node *nodecollect::item(int i){ return v[i]; } void nodecollect::push(node* n){ v.push_back(n); count++; } void node::appned(node *n){ if(child){ node *n1=child; while(n1->next){ n1=n1->next; } n1->next=n; count++; n->parent=this; }else{ child=n; count++; n->parent=this; } } void node::insert(int i,node *n){ if(i==0){ n->next=child; n->parent=this; count++; child=n; }else if(i==count){ appned(n); }else{ node *n1=child,*n2=0; int i1=0; while(i1!=i){ n2=n1; n1=n1->next; i1++; } n2->next=n; n->next=n1; count++; n->parent=this; } } void node::removechild(int i){ if(i==0){ node *n=child; child=child->next; delete n; }else{ node *n=child,*n1=0; int i1=0; while(i1!=i){ n1=n; n=n->next; i1++; } n1->next=n->next; delete n; } } string node::getattr(string s){ string ss; char *i=strstr(data.data(),s.data()); if(i && (*(i-1)==' ' || *(i-1)=='/r' || *(i-1)=='/n' || *(i-1)=='/t') && (*(i+s.length())==' ' || *(i+s.length())=='=')){ char *i1=strstr(i+1,"/""); char *i2=strstr(i1+1,"/""); i1++; while(i1!=i2){ ss+=*i1; i1++; } } return ss; } void node::setattr(string k,string v){ char *i=strstr(data.data(),k.data()); if(i && (*(i-1)==' ' || *(i-1)=='/r' || *(i-1)=='/n' || *(i-1)=='/t') && (*(i+k.length())==' ' || *(i+k.length())=='=')){ char *i1=strstr(i+1,"/""); char *i2=strstr(i1+1,"/""); string d=i2; data=data.substr(0,i1-data.data()+1); data+=v; data+=d; }else{ data=data+' '+k+"="+'/"'+v+'/"'; } }

给个实例：

main(){
 FILE *f=fopen("c://a.xml","r");
 char buf[1024]={0};
 fread(buf,1,1024,f);
 fclose(f);

xml x;
x.loadstring(buf);
x.out();
}

      上面给出了不少接口，但没有一一都实现，不过我想看懂代码的明白其实已经够用了，这两天有点累了，想休息下。

       本文有不足之处，还望大家多多指正。