社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 9034阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* 9_ICNG%  
**SiteFileFetch.java  c9''  
*/ ?zJpD8e  
package NetFox; L gmvKW|  
import java.io.*; $m1<i?'m  
import java.net.*; >e5 *prx+  
Hs"(@eDV&J  
2s*#u<I  
public class SiteFileFetch extends Thread { gV1[3dW  
<HWS:'1  
wyx(FinIH  
SiteInfoBean siteInfoBean = null; //文件信息Bean L(;WxHL  
long[] nStartPos; //开始位置 fjo{av~]y  
long[] nEndPos; //结束位置 %x; x_  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 c;f!!3&  
long nFileLength; //文件长度 zHWSE7!  
boolean bFirst = true; //是否第一次取文件 "\"DCDKmG  
boolean bStop = false; //停止标志 &ej8mq"\  
File tmpFile; //文件下载的临时信息 (9\;A*CZ  
DataOutputStream output; //输出到文件的输出流 Op.8a`XLt&  
>!e<}84b  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) {>3\ N0e5  
public SiteFileFetch(SiteInfoBean bean) throws IOException 5F+APz7  
{ JE 5  
siteInfoBean = bean; ;?fS(Vz~  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); B@Co'DV[/]  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); }/dRU${!  
if(tmpFile.exists ()) zo{/'BnU  
{ XKL3RMF9r  
bFirst = false; R9We/FhOY  
read_nPos(); t9gfU5?  
} P`4]-5gE  
else ->z54 T  
{ 8eIUsI.o  
nStartPos = new long[bean.getNSplitter()]; g]@ (E  
nEndPos = new long[bean.getNSplitter()]; /gcEw!JS  
} Bm$"WbOq*R  
Xm2\0=v5;  
2Q7R6*<N:  
'XQ`g CF=  
} ]  H~4  
iF5'ygR-Z  
zIC;7 5#  
public void run() 5V[oE\B  
{ e<7.y#L  
//获得文件长度 l5%G'1w#,j  
//分割文件 2I3h M D0  
//实例FileSplitterFetch C,V%B  
//启动FileSplitterFetch线程 kNqS8R|  
//等待子线程返回 v`J*ixZ7t  
try{ _cTh#t ^  
if(bFirst) 7qOa ;^T  
{ _LP/!D  
nFileLength = getFileSize(); $CTSnlPq  
if(nFileLength == -1) -&82$mj  
{ q/3ziVd7p  
System.err.println("File Length is not known!"); m p<1yY]  
} B!{d-gb  
else if(nFileLength == -2) d\MLOXnLq;  
{ iUMY!eqp  
System.err.println("File is not access!"); /[:dp<  
} 5Dp#u  
else a8u 9aEB  
{ r`&-9"+  
for(int i=0;i<nStartPos.length;i++) I{JU-J k|  
{ nKR{ug>I)  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); =U[3PC-N @  
} =/<LSeLxH  
for(int i=0;i<nEndPos.length-1;i++) ~pa!w?/bQ  
{ `k(yZtb  
nEndPos = nStartPos[i+1]; u&G.4QQF  
} z"D.Bm~ ]  
nEndPos[nEndPos.length-1] = nFileLength; 0![ +Q4"  
} $'W}aER  
} w6`9fX6{h  
_'4A|-9  
Q 4CjA3  
//启动子线程 6nhMP$h  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )9,  
for(int i=0;i<nStartPos.length;i++) HW&%T7 a  
{ Li*eGlId  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OY[e.N t&  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |6G m:jV  
nStartPos,nEndPos,i); r "$.4@gc  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (E,T#uc{  
fileSplitterFetch.start(); y@CHR  
} P"sA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kq\)MQ"/X  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |t$Ma'P  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nRd)++  
nEndPos = " + nFileLength); I ZQHu h  
// fileSplitterFetch[nPos.length-1].start(); kw2T>  
.^J2.>.  
@FdSFQ/9  
//等待子线程结束 Em[DHfu1Q  
//int count = 0; "~TA SX_?  
//是否结束while循环 a>\vUv*  
boolean breakWhile = false; vb9OonE2  
8Sz})UZ  
oyo(1 >  
while(!bStop) -i-?.:  
{ :qC '$dO!  
write_nPos(); vn/.}GkpU  
Utility.sleep(500); x@8a''  
breakWhile = true; hY`\&@  
q -8t'7  
\"hJCP?,  
for(int i=0;i<nStartPos.length;i++) fhB}9i^]tg  
{ dz Zb  
if(!fileSplitterFetch.bDownOver) g+X}c/" .  
{ r(gXoq_w  
breakWhile = false; ftH:r_"O#  
break; A$6$,h  
}  }-~l!  
} EJ2yO@5O  
if(breakWhile) uslQ*7S[^  
break; :6$>_m=i  
n]he-NHP  
,AT[@  
//count++; (XoH,K?{z  
//if(count>4) vm>b m  
// siteStop(); I!^O)4QRx  
} O*#*%RL|  
nT2)E&U6%  
=*Bl|;>6  
System.err.println("文件下载结束!"); Yup3^E w&  
} B7imV@<  
catch(Exception e){e.printStackTrace ();} ?IpLf\n-  
} _YRE (YZ/  
j&k6O1_  
.`&F>o(A  
//获得文件长度 $ tl\UH7%2  
public long getFileSize() y|wc ,n%L>  
{ av~5l4YL  
int nFileLength = -1; |fo0  
try{ TsTPj8GAl[  
URL url = new URL(siteInfoBean.getSSiteURL()); kwsp9 0)  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cp h:y  
httpConnection.setRequestProperty("User-Agent","NetFox"); 0]4(:(B  
qgrg CJ  
4!KoFoZt*  
int responseCode=httpConnection.getResponseCode(); iTaWup  
if(responseCode>=400) NF? vg/{  
{ ]kboG%Dl?9  
processErrorCode(responseCode); 33}oO,}t,  
return -2; //-2 represent access is error l} qE 46EL  
} A<y nIs<  
M'/aZ# b  
i7ly[6{^pr  
String sHeader; Tyck/ EO  
IH"6? 9nd  
Fgh]KQ/5  
for(int i=1;;i++) ]~3U  
{ 0Zg%+)iy@  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +sJrllrE(  
//Utility.log(in.readLine()); 4 uQT5  
sHeader=httpConnection.getHeaderFieldKey(i); 2@ Z(P.Gh  
if(sHeader!=null) twx[ s$O'b  
{ (IPY^>h  
if(sHeader.equals("Content-Length")) Z:_D0jG  
{ ()H:UvM=t  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); jQ)T67  
break; e$pMsw'MJ  
} .(WQYOMl0  
} z0do;_x]E  
else `ta7Gc/:UY  
break; &@3H%DP}Ql  
} -ne Kuj  
} =J~ x  
catch(IOException e){e.printStackTrace ();} {,L+1h  
catch(Exception e){e.printStackTrace ();} YtWJX kB  
/g4f`$a  
=ha{Ziryo  
Utility.log(nFileLength); &/Q0  
p"U, G -_  
{.?/)  
return nFileLength; ',S'.U  
} J.| +ID+  
|.3DD"*  
Xp}Yw"7  
//保存下载信息(文件指针位置) ~T89_L  
private void write_nPos() U,.![TP  
{ "T- `$'9  
try{ (zFi$  
output = new DataOutputStream(new FileOutputStream(tmpFile)); E^ SH\5B  
output.writeInt(nStartPos.length); (!zy{;g|  
for(int i=0;i<nStartPos.length;i++) $-*!pRaVU  
{ Dmu/RD5X:  
// output.writeLong(nPos); <(-hx+^  
output.writeLong(fileSplitterFetch.nStartPos); `FC(  
output.writeLong(fileSplitterFetch.nEndPos); 5hy""i  
} ziCHjqT  
output.close(); _"w2Uq  
} Xqm::1(-(  
catch(IOException e){e.printStackTrace ();} ` 5C~  
catch(Exception e){e.printStackTrace ();} qC?:*CXH  
} 5kz)5,KjM  
x a06i#  
82DmG@"s2  
//读取保存的下载信息(文件指针位置) =>! Y{: y(  
private void read_nPos() EB8\_]6XJ  
{ x3"#POp  
try{ oGRhnP'PF+  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); se>MQM5 )  
int nCount = input.readInt(); _}En/V_  
nStartPos = new long[nCount]; v3jg~"!  
nEndPos = new long[nCount]; WpRc)g :  
for(int i=0;i<nStartPos.length;i++) 6Avw-}.7>  
{ %&Q$dzgb_  
nStartPos = input.readLong(); IDG}ZlG  
nEndPos = input.readLong(); 7fba-7-P  
} '4#}e[e  
input.close(); `6xkf&Kt  
} @>U-t{W  
catch(IOException e){e.printStackTrace ();} f|tjsZxQ  
catch(Exception e){e.printStackTrace ();} B,=H@[Fj  
} W!>.$4Q9  
7 !JQB  
fL=~NC"  
private void processErrorCode(int nErrorCode) >b{q.  
{ H"dJ6  
System.err.println("Error Code : " + nErrorCode); q*7VqB  
} -#HA"7XOE  
Aw5HF34J  
{ >)#HD  
//停止文件下载 ssN6M./6  
public void siteStop() E`uY1B[c  
{ n@,G8=J?  
bStop = true; Xn%pNxUL  
for(int i=0;i<nStartPos.length;i++) csW43&  
fileSplitterFetch.splitterStop(); FK5 <6n,U  
_zwG\I|Q  
pv Gf\pu  
} S-|)QGxV6  
} 65aK2MS@  
//负责部分文件的抓取  q;][5  
**FileSplitterFetch.java xM&Wgei]10  
*/ /VN f{p  
package NetFox; OD6\Mr2=  
#/<&*Pu5t  
TO?R({yx*  
import java.io.*; [c|]f_ZdK  
import java.net.*; 5MtLT#C3r  
wlqpn(XR  
jGpN,/VQa  
public class FileSplitterFetch extends Thread { /*X2c6<d  
O4V.11FnW  
NP/Gn6fr  
String sURL; //File URL 2h1vVF3  
long nStartPos; //File Snippet Start Position O%5 r[  
long nEndPos; //File Snippet End Position 'DL`Ee\  
int nThreadID; //Thread's ID E4~<V=2l  
boolean bDownOver = false; //Downing is over 42(Lb'G  
boolean bStop = false; //Stop identical ?-dX`n  
FileAccessI fileAccessI = null; //File Access interface ,l:ORoND  
%~2YE  
dE4L=sTEsy  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException |n,<1QY  
{ O\"3J(y,  
this.sURL = sURL; 4O)1uF;  
this.nStartPos = nStart; HiR[(5vnf  
this.nEndPos = nEnd; lrIS{MJ+-  
nThreadID = id; Hn%xDJ'  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 opy("qH  
} DkvF5c&  
]dGw2y  
pxCK;]  
public void run() uF9C -H@:  
{ %}Ss,XJ  
while(nStartPos < nEndPos && !bStop) pgQV/6  
{ Af'" 6BS  
p8h9Ng* &`  
w1OI4C)~  
try{ "AnC?c9?-^  
URL url = new URL(sURL); 4,CXJ2  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FtfKe"qw  
httpConnection.setRequestProperty("User-Agent","NetFox"); B"TAjB& *  
String sProperty = "bytes="+nStartPos+"-"; #t: S.A@  
httpConnection.setRequestProperty("RANGE",sProperty); 3L_\`Ia9  
Utility.log(sProperty);  a1t4Dd  
U |Jo{(Y  
5qZ1FE  
InputStream input = httpConnection.getInputStream(); 'E/^8md>  
//logResponseHead(httpConnection); 2.l Z:VLN  
G IT>L  
Jrti cK$  
byte[] b = new byte[1024]; *E/`KUG]  
int nRead; <SgM@0m  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vzdh8)Mu\  
{ qln3 k`  
nStartPos += fileAccessI.write(b,0,nRead); .<x&IJ /  
//if(nThreadID == 1) M<.d8?p )  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cDFO;Dr  
} 1 u| wMO  
aWWU4xe  
 -QM: q  
Utility.log("Thread " + nThreadID + " is over!"); Po__-xN>Q  
bDownOver = true; i|w81p^o  
//nPos = fileAccessI.write (b,0,nRead); h_:C+)13`x  
} g`vny)\7/  
catch(Exception e){e.printStackTrace ();} ;t<QTGJ  
}  \N!AXD  
} <acUKfpY  
P"y`A}Bx  
9`I _Et  
//打印回应的头信息 hb zC#@ q  
public void logResponseHead(HttpURLConnection con) 544X1Ww2  
{ tiB_a}5IB  
for(int i=1;;i++) 3DiLk=\~  
{ !}v=N";c  
String header=con.getHeaderFieldKey(i); 9[b<5Llt  
if(header!=null) -Zf@VW,NI  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Xjo5v*Pu  
Utility.log(header+" : "+con.getHeaderField(header)); \r /ya<5  
else z3&]%Q&  
break; L+Xc-uv["p  
} Tl$ [4heE  
} - }7e:!.  
/y _O 4  
^W'fA{sr  
public void splitterStop() y#Fv+`YDl  
{ 6x h:/j3  
bStop = true; 10<x.8fSP  
} ;1`fC@rI  
WN{ 9  
 87<-kV  
} E*.{=W }C  
q qpgy7  
(]0%}$Fo  
/* UR7g`/  
**FileAccess.java P3cRl']  
*//文件访问(定位,写) [Sr,h0h6  
package NetFox; y4*U6+#.  
import java.io.*; 2 ^mJ+v<  
C~nzH,5  
!/}O>v~o  
public class FileAccessI implements Serializable{ P_?gq>E8  
WF1px%  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "^w]_^GD$d  
RandomAccessFile oSavedFile; 8TGOx%}i  
long nPos; YVYu:}e3)  
`tHvD=`m.  
;i Fz?d3;  
public FileAccessI() throws IOException :"=ez<t  
{ lJu;O/  
this("",0); J)`-+}7$v  
} B:gjAb}9T  
J6U$qi  
kSR\RuY*  
public FileAccessI(String sName,long nPos) throws IOException +V m}E0Ov  
{ \@8+U;d  
oSavedFile = new RandomAccessFile(sName,"rw"); zA$k0p  
this.nPos = nPos; _AQb6Nb  
oSavedFile.seek(nPos); .QA }u ,EN  
} 1u: gFUb  
}._eIx"  
5&v~i\Q  
public synchronized int write(byte[] b,int nStart,int nLen) DE%KW:Hug  
{ ^Wc@oa`  
int n = -1; <F}_ /q1  
try{ {DU`[:SQZg  
oSavedFile.write(b,nStart,nLen); A%`[mc]4#  
n = nLen; ppZDGpp  
} Zb1<:[  
catch(IOException e) Tav*+  
{ ?Lyxw]  
e.printStackTrace (); Q^ pmQ  
} _9=Yvc=  
Ag&0wN+jTM  
k 9L? +PD  
return n; A9wh(P0\  
} LG<J;&41~S  
W}5xmz  
N'g>MBdI  
} b]x4o#t  
oJ4 AIQjB  
m|{3),#V  
/* MFb9H{LA  
**SiteInfoBean.java H`0|tepz  
*/ R~)\3] "2m  
package NetFox; XzIl`eH  
z"0I>gl  
cUvz2TK  
public class SiteInfoBean { (+B5|_xQu  
*g6n  
+R|z{M)*  
private String sSiteURL; //Site's URL | h;0H`  
private String sFilePath; //Saved File's Path M7@2^G]p  
private String sFileName; //Saved File's Name M+w=O!dq  
private int nSplitter; //Count of Splited Downloading File h&--,A >  
k~jP'aD  
jV4\A  
public SiteInfoBean() hJZV}a|  
{//nSplitter的缺省值为5 i(>4wK!!  
//default value of nSplitter is 5 _i20|v   
this("","","",5); paKSr|O  
} }Q=!Y>Tc  
BK,{N0  
Bh;7C@dq  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iZM+JqfU|D  
{ Q$="_y2cTA  
sSiteURL= sURL; k +H3Bq  
sFilePath = sPath; QWzB6H]  
sFileName = sName; JV]^zW  
this.nSplitter = nSpiltter; mg*qiScfW  
Ry%Mej:  
]Bjyi[#bg  
} 2oNk 93D  
A29gz:F(  
m^GJuP LW  
public String getSSiteURL()  :}@g6   
{ F W/W%^  
return sSiteURL; o]; [R  
} @I_8T$N=  
iZaI_\"__  
y0'Rmk,  
public void setSSiteURL(String value) b\-&sM(W"  
{ h-Fn?  
sSiteURL = value;  B[Zjfc  
} }>VG~u8  
v?& -xH-S  
9hOJvQ2U]  
public String getSFilePath() H\qC["  
{ &!/}Qp  
return sFilePath; pXJpK@z  
} rzh#CnL3  
#m{UrTC  
;)!Sp:mHX  
public void setSFilePath(String value) X&0 uI*r  
{ G|( ]bvJ?  
sFilePath = value; p' +  
} Gcig*5   
l,,> & F  
X!m9lV<  
public String getSFileName() V??dYB(  
{ Lz:(6`S  
return sFileName; *T~Ve;3h;  
} $aN&nhoO<  
Mi/&f   
+TQ47Z c  
public void setSFileName(String value) :1iqT)&|8F  
{ ^sVX)%  
sFileName = value; p TeOW9  
} Kwg4sr5"D  
!-,t'GF(  
-eN\ !  
public int getNSplitter() WC|.g,9#  
{ *7h!w!LN~  
return nSplitter; 7LU}Iiv  
} dO4{|(z  
6Qx#%,U^ J  
;ByOth|9P  
public void setNSplitter(int nCount) k&. Jk B"  
{ ui@2s;1t  
nSplitter = nCount; }b0; 0j  
} "V$Bnz\n  
} |jVM&R2s  
l?Fb ='#  
7 <Q5;J&;  
/* ;\\@q"n%<  
**Utility.java FDv+*sZ  
*/ *0>mB  
package NetFox; ,iv|Pq $!  
2w-51tqm  
I= .z+#Y  
public class Utility { ZG du|  
,i,q!M{-  
cPU/t kc  
public Utility() =n' 4?W@  
{ E4W zU  
LJ(1RK GCz  
C,pJ`:P  
} T7d9ChU\#.  
i6 (a@KRY  
//线程睡眠 u*#ZXW  
public static void sleep(int nSecond) y:v xE8$Q  
{ Kbb78S30  
try{ =T7A]U]  
Thread.sleep(nSecond); %bD}m!  
} L   
catch(Exception e) `/MvQ/  
{ }A:<%N  
e.printStackTrace (); ~~6^Sh60g  
} fz3 lV  
} |-CnT:|o  
\#>T~.Y7K  
//日志 viAMr"z  
public static void log(String sMsg) a<A+4uXyD  
{ W5'3$,X9  
System.err.println(sMsg); , E$@=1)  
} A?oXqb  
k~|-gf FP  
}irn'`I  
public static void log(int sMsg) 4#'(" #R  
{ s#S%#LM  
System.err.println(sMsg); iK IOh('G  
} U7DCx=B  
} ,~);EC=`  
i9D0]3/>  
}=2;  
/* nWvuaQ0}  
**TestMethod.java Bs M uQ|!  
*/ xwH?0/  
package NetFox; 6y5A"-  
/LM4- S  
-.|4Y#b:&  
public class TestMethod { DS -fjH\  
}rdIUlVO\  
)C.yF)Ql  
public TestMethod() 0'r%,0  
{ ///xx/weblogic60b2_win.exe U5]pi+r  
try{ gBf4's  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u<n`x6gL  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3<?XTv-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); cM_ Fp  
fileFetch.start(); bhs(Qzx  
} O3.C:?;x  
catch(Exception e){e.printStackTrace ();} sIl33kmv  
-[Qvg49jy  
V >,Z-&.%  
} ;_:Ool,  
!4rPv\   
M- 0i7%  
public static void main(String[] args) #2tCV't  
{ m4[g6pNx~  
new TestMethod(); xc?}TPpt  
} <g9"Cr`  
} w^1Fi8+  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
10+5=?,请输入中文答案:十五