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
  • 12076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
/* Q>=-ext}q  
**SiteFileFetch.java gI{ =0  
*/ <HF-2?`  
package NetFox; 6V2j*J  
import java.io.*; B\[-fq  
import java.net.*; 3gc"_C\$  
%ek"!A  
h<Wg3o  
public class SiteFileFetch extends Thread { ,QvYTJ{  
F7T E|LZ  
]fE3s{y &-  
SiteInfoBean siteInfoBean = null; //文件信息Bean p=B?/Sqa  
long[] nStartPos; //开始位置 y(v_-6b  
long[] nEndPos; //结束位置 ao$):,2*  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 G9Qe121m  
long nFileLength; //文件长度 (6R4 \8z2  
boolean bFirst = true; //是否第一次取文件 &@6 GI<  
boolean bStop = false; //停止标志 g$w6kz_[  
File tmpFile; //文件下载的临时信息 A(+:S"|@  
DataOutputStream output; //输出到文件的输出流 Hf%_}Du /`  
SF< [FM%1  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) "PzP; Br  
public SiteFileFetch(SiteInfoBean bean) throws IOException DA=1KaJ.  
{ v`B4(P1Z  
siteInfoBean = bean; jdM=SBy7q  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); S}cF0B1E*  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?Y3@"rdR  
if(tmpFile.exists ()) m}5q]N";x  
{ i&&qbZt  
bFirst = false; 5UO k)rOf  
read_nPos(); "8HE^Po/pn  
} s$GF 95^  
else Spgg+;9  
{ B 8{ uR  
nStartPos = new long[bean.getNSplitter()]; jczq `yW  
nEndPos = new long[bean.getNSplitter()]; sRq U]i8l  
} Pp*}R2  
Ae49n4J  
I4il R$jg  
YPszk5hn  
} ezZph"&  
Ttv'k*$cP  
"={L+di:M  
public void run() v!trsjb  
{ `?uPn~,e8  
//获得文件长度 +< KNY  
//分割文件 "}zda*z8  
//实例FileSplitterFetch &fSTR-8ev#  
//启动FileSplitterFetch线程 xl2g0?  
//等待子线程返回 LgHJo-+>  
try{ d(S}NH  
if(bFirst) 10MU-h.)  
{ ({M?Q>s  
nFileLength = getFileSize(); % {Q-8w!  
if(nFileLength == -1) !8$RBD %  
{  YqU/\f+  
System.err.println("File Length is not known!"); GuO`jz F  
} f1Zt?=  
else if(nFileLength == -2) ><Uk*mwL  
{ T"!EK&  
System.err.println("File is not access!"); l!IGc:  
} ``9 GY  
else ^,V[nfQR  
{ xvDI 4x&  
for(int i=0;i<nStartPos.length;i++) q# vlBL  
{ ,%hj cGX11  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); w^o }E)O  
} :3? |VE F  
for(int i=0;i<nEndPos.length-1;i++) ~E*d G  
{ DB@EVH  
nEndPos = nStartPos[i+1]; ;&,.TC?l  
} Bq!cY Wj  
nEndPos[nEndPos.length-1] = nFileLength; xo WT*f  
} wPnybb{  
} B*,?C]0{  
c3k|G<C2  
NHkL24ve  
//启动子线程 1q]c7"  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; AuCWQ~  
for(int i=0;i<nStartPos.length;i++) FT/amCRyT  
{ }Bff,q  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A}G|Yfn  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ( v@jc8y  
nStartPos,nEndPos,i); VJ{pN~_1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SI*^f\lu  
fileSplitterFetch.start(); < y>:B}9'  
} \FifzKA  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DJP 6TFT&G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {$fsS&aPg  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g-@h>$< 1  
nEndPos = " + nFileLength); Nl*i5 io  
// fileSplitterFetch[nPos.length-1].start();  r(`nt-o@  
7& 6Y  
_/ Os^>R  
//等待子线程结束 >. LKct*5K  
//int count = 0; l`gTU?<xd  
//是否结束while循环 G;]:$J  
boolean breakWhile = false; _N'75  
)|]Z>>%t  
)+Y&4Qu  
while(!bStop) hI~SAd ,#A  
{ !k<:k "7  
write_nPos(); ]rW8y%yD  
Utility.sleep(500); AS;.sjgk  
breakWhile = true; G|9B )`S  
z{?4*Bq  
J_xG}d  
for(int i=0;i<nStartPos.length;i++) T:!MBWYe|  
{ 5 09Q0 [k  
if(!fileSplitterFetch.bDownOver) z[&s5"  
{ ]k+m=OR{/  
breakWhile = false; _;e\:7<m  
break; D,rZ0?R  
} Z+idLbIs  
} +?d}7zh  
if(breakWhile) HDS"F.l5  
break; \*"`L3  
xl] ;*&  
=B(mIx;m  
//count++; G6O/(8  
//if(count>4) PZM42"[&  
// siteStop(); MF.[8Zb  
} T;?+kC3  
K.DXJ UR  
8tQ|-l *  
System.err.println("文件下载结束!"); vJC f~'  
} t ;-L{`mW  
catch(Exception e){e.printStackTrace ();} H_B~P%E@]  
} =!<G!^  
^M Ey,  
n Ga1a  
//获得文件长度 A=`* r*  
public long getFileSize() <qY5SV,  
{ crn k|o  
int nFileLength = -1; CLK^gZ  
try{ [7\>"v6  
URL url = new URL(siteInfoBean.getSSiteURL()); e4.&aIC[  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6 = gp:I  
httpConnection.setRequestProperty("User-Agent","NetFox"); Hg(5S,O2  
y\[r(4h  
JO1 ,TtA  
int responseCode=httpConnection.getResponseCode(); Ew4 g'A:H  
if(responseCode>=400) mm,lhIh  
{ ULl_\5s2  
processErrorCode(responseCode); y1C/v:;  
return -2; //-2 represent access is error lbkL yp2  
} #T% zfcUj  
_413\`%8?  
xzk}[3P{  
String sHeader; w0Ij'=:  
Y @}FL;3  
D4Sh9:\  
for(int i=1;;i++) uva\0q  
{ E`)Qs[?Gk  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dlD}Ub  
//Utility.log(in.readLine()); :p-Y7CSSu  
sHeader=httpConnection.getHeaderFieldKey(i); iJP{|-h  
if(sHeader!=null) Z"tQp Jg  
{ qrDcL>Hrn  
if(sHeader.equals("Content-Length")) /`+7_=-  
{ *K)0UKBr  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4e9E' "8%  
break; b UvK  
} l)8sw=  
} 7/>a:02  
else abWl ut  
break; Sdc*rpH"(  
} Yx1 D)  
} RvW.@#EH0  
catch(IOException e){e.printStackTrace ();}  aZgNPw  
catch(Exception e){e.printStackTrace ();} )w"0w(   
;.s: X  
t)I0lnbs  
Utility.log(nFileLength); \"d?=uFe  
?}sOG?{  
o#e7,O  
return nFileLength; j'Wp  
} SE!L :  
e1P7 .n}  
-,GEv%6c  
//保存下载信息(文件指针位置) E1W:hGI  
private void write_nPos() c{>|o  
{ A,c'g}:  
try{ \_ -DyD#3  
output = new DataOutputStream(new FileOutputStream(tmpFile)); :_H>SR:  
output.writeInt(nStartPos.length); Jsn <,4DO8  
for(int i=0;i<nStartPos.length;i++) ]kS7n @8  
{ q^Inb)FeN  
// output.writeLong(nPos); ]{Ek[Av  
output.writeLong(fileSplitterFetch.nStartPos); xIgql}.  
output.writeLong(fileSplitterFetch.nEndPos); c]v +  
} Taasi` k  
output.close(); Mi74Xl i  
} QymD-A"P  
catch(IOException e){e.printStackTrace ();} O71BM@2<  
catch(Exception e){e.printStackTrace ();} s.y}U5Ty?P  
} g1qi\axm  
8]C1K Zs  
7) 0q--B  
//读取保存的下载信息(文件指针位置) 2U%qCfh6|  
private void read_nPos() }n95< {  
{ [TCRB`nTQF  
try{ _,Q[2gQ5N  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !$r9C/k  
int nCount = input.readInt(); e?<D F.Md+  
nStartPos = new long[nCount]; U;gp)=JNT  
nEndPos = new long[nCount]; m!Af LSlwm  
for(int i=0;i<nStartPos.length;i++) /*P7<5n0  
{ -f.R#J$2  
nStartPos = input.readLong(); .Cr1,Po  
nEndPos = input.readLong(); &<h?''nCy  
} R 3G@ G  
input.close(); iQ{z6Qa  
} C BlXC7_Mi  
catch(IOException e){e.printStackTrace ();} ;+%Z@b%  
catch(Exception e){e.printStackTrace ();} if@,vc  
} <gcmsiB|  
DMMLzS0A  
W5I=X] &  
private void processErrorCode(int nErrorCode) 'w6hW7"L  
{ i+AUQ0Zbf6  
System.err.println("Error Code : " + nErrorCode); [q$e6JwAt  
} pqq?*\W&[v  
\HG$V>2  
} J(1V!EA  
//停止文件下载 ]ymC3LV]  
public void siteStop() .K7C-Xn=  
{ 6Ahr_{  
bStop = true; 7TdQRB  
for(int i=0;i<nStartPos.length;i++) 0||F`24  
fileSplitterFetch.splitterStop(); b,Lw7MY}[  
kW(Kh0x  
A'~#9@l<  
} kaO{#i2-  
} yoW> BX  
//负责部分文件的抓取 5)*6V&  
**FileSplitterFetch.java -fPT}v  
*/ e YDUon  
package NetFox; -yA3 RP  
"Q?_ EEn  
:rL?1"   
import java.io.*; uk6g s)qxC  
import java.net.*; 0BFz7  
! tr9(d  
`Sx.|`x8  
public class FileSplitterFetch extends Thread { w"6aha*%7  
l $w/Fz  
yM|g|;U  
String sURL; //File URL qmID-t"  
long nStartPos; //File Snippet Start Position s7M}NA 0  
long nEndPos; //File Snippet End Position ^$}/|d(  
int nThreadID; //Thread's ID Gc^t%Ue-H)  
boolean bDownOver = false; //Downing is over cIZ[[(Db  
boolean bStop = false; //Stop identical ]b )!YPo  
FileAccessI fileAccessI = null; //File Access interface D O%Pwfkd  
, QA9k$`  
ifHU|0_=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4y>(RrVG  
{ K=o:V&  
this.sURL = sURL; 6Ty 3e|do  
this.nStartPos = nStart; QES^^PQe:  
this.nEndPos = nEnd; req-Q |  
nThreadID = id; XLocg  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 QE*%HR'  
}  z \^  
Se/ss!If  
N-Z^G<[q.  
public void run() ,\}k~ U99  
{ ()B7(Y  
while(nStartPos < nEndPos && !bStop) 9R>~~~{-Go  
{ r},lu=em  
!"%S#nrL$  
vlAy!:CV  
try{ UeNF^6sWu0  
URL url = new URL(sURL); L5&K}F]r^  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TR?Bvy2s:g  
httpConnection.setRequestProperty("User-Agent","NetFox"); FR(QFt!g  
String sProperty = "bytes="+nStartPos+"-"; w_!%'9m>  
httpConnection.setRequestProperty("RANGE",sProperty); 2$Wo&Q^_  
Utility.log(sProperty); Onyh1  
n5\}KZh  
w -M7opkq  
InputStream input = httpConnection.getInputStream(); J7Sx!PQ  
//logResponseHead(httpConnection); u9,=po=+7f  
JeL~]F  
18rp; l{  
byte[] b = new byte[1024]; -`g J  
int nRead; 2;h+;G  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MU*It"@}2  
{ cPSti  
nStartPos += fileAccessI.write(b,0,nRead); pSXEJ 2k  
//if(nThreadID == 1) ?F25D2[(  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); eN4t1 $  
} -zR.'x%  
g kn)V~ij  
p_;r%o=  
Utility.log("Thread " + nThreadID + " is over!"); D>S8$]^Dm  
bDownOver = true; '?b\F~$8  
//nPos = fileAccessI.write (b,0,nRead); <a fO 6?`  
} ~7dF/Nn5  
catch(Exception e){e.printStackTrace ();} oHk27U G  
} [)0 R'xL6  
} y%FYXwR{  
gz#+  
7<vy;"wB  
//打印回应的头信息 ,k\/]9  
public void logResponseHead(HttpURLConnection con) *iYMX[$  
{ ~Z7)x7 z  
for(int i=1;;i++) 1S&0  
{ \UhGGg%  
String header=con.getHeaderFieldKey(i); R7,p ukK  
if(header!=null) UL[uh@4  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z41D^}b  
Utility.log(header+" : "+con.getHeaderField(header)); AT-0}9z{  
else lqauk)(A0  
break; 8'n#O>V@  
} HMhLTl{;  
} d0Tg qO{  
*0lt$F$~b  
X&/(x  
public void splitterStop() !%X>rGkc  
{ #U:0/4P(  
bStop = true; &D)Hz  
} mcCB7<. e  
w gmWo8  
yX`J7O{=  
} eXc[3ceUr  
5R)[Ou.  
RZ<.\N (M  
/* ": nI_~q  
**FileAccess.java =?^-P{:\?  
*//文件访问(定位,写) 75<el.'H  
package NetFox; )G mb? !/^  
import java.io.*; 3mybG%39  
am3V9 "\  
UC.8DaIPN  
public class FileAccessI implements Serializable{ DhHtz.6  
N-Qu/,~+  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x4@MO|C  
RandomAccessFile oSavedFile; Cy]"  
long nPos; a$A2IkD  
xJ$Rs/9C  
haN"/C^  
public FileAccessI() throws IOException B5 D3_ iX]  
{ Q:kwQg:~  
this("",0); 0= 2H9v  
} IcRM4Ib))Q  
87R%ke  
e#K rgUG  
public FileAccessI(String sName,long nPos) throws IOException x-tm[x@;o  
{ Hi$#!OU  
oSavedFile = new RandomAccessFile(sName,"rw"); `Yg7,{A\J  
this.nPos = nPos; \MF3CK@/  
oSavedFile.seek(nPos); JATS6-Lz`  
} .V7Y2!4TE  
<1TlW ~q<  
' l|41wxk  
public synchronized int write(byte[] b,int nStart,int nLen) dvC0 <*V  
{ ex{)mE4Cd  
int n = -1; Fka1]|j9  
try{ k>7gy?Y!K<  
oSavedFile.write(b,nStart,nLen); g9M')8a n  
n = nLen;  b$PT_!d  
} C3]\$  
catch(IOException e) }klE0<W|5\  
{ N`J:^,H  
e.printStackTrace (); L00Sp#$\  
} 2*N&q|ED  
6\%r6_.d  
B>ms`|q=l  
return n; xV"6d{+  
} ?f(pQy@V  
~JIywzcf8  
9yO{JgKA  
} qn5y D!1  
@?'t@P:4  
~JAH-R  
/* #8P#^v]H  
**SiteInfoBean.java 1'(_>S5CG  
*/ .`:oP&9r  
package NetFox; ' m  
(xI)"{   
Tnzco  
public class SiteInfoBean { z4 GN8:~x  
,R7=]~<io"  
SH .9!lQv  
private String sSiteURL; //Site's URL Gw{Gt]liq  
private String sFilePath; //Saved File's Path aS c#&{  
private String sFileName; //Saved File's Name A@9U;8k  
private int nSplitter; //Count of Splited Downloading File 6 ,7/8  
?j &V:kF  
%i;r]z-  
public SiteInfoBean() {JCSR2BB  
{//nSplitter的缺省值为5 v!WU |=u  
//default value of nSplitter is 5 QC$=Fs5+  
this("","","",5); QCZ,K" y  
} U>e3_td3,  
6n2Vx1b  
_ C7abw-  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n's2/9x  
{ w`H.ey  
sSiteURL= sURL; [Q2S3szbt6  
sFilePath = sPath; 7j9D;_(.^$  
sFileName = sName; o=mq$Z:}  
this.nSplitter = nSpiltter; hNu>s  
S3%.-)ib  
">0/>>Ry  
} d A_S"Zc  
eO|^Lu]+  
jhjW* F<u  
public String getSSiteURL() ]# tGT0   
{ $Uv<LVd(  
return sSiteURL; *7:u-}c!  
} [TiT ff&LV  
w>H%[\Qs  
/ K2.V@T  
public void setSSiteURL(String value) ;o~+2Fir  
{ ~frPV8^DP  
sSiteURL = value; `dG.L  
} <>&e/  
J4Q)`Y\~  
r'mnkg2,  
public String getSFilePath() _qO;{%r  
{ orcZ yYU  
return sFilePath; /-G qG)PX  
} !`O_VV`/@  
G#9o?  
}J'5EAp  
public void setSFilePath(String value) >#"jfjDuR  
{ #cSw"A  
sFilePath = value; {2'74  
} j. ks UJ  
ims=-1,  
&vJ(P!2f<  
public String getSFileName() 9H !B)  
{ ^a:vJ)WB7  
return sFileName; e4>L@7  
} IGF37';;  
xVh\GU855  
Cn6n4, 0  
public void setSFileName(String value) )<]w23i  
{ q>(I*=7  
sFileName = value; 1?e>x91  
} Oo3qiw  
_.Z&<.lJ  
<'o'H  
public int getNSplitter() A .jp<>  
{ MQbNWUi  
return nSplitter; ..Uw8u/  
} 2]_4&mU  
R&x7Iq:=D  
]P}K3tN%]  
public void setNSplitter(int nCount) &bS"N)je  
{ @gu77^='  
nSplitter = nCount; }jyS\drJ  
} (to/9OrG  
} 0$F _hZU  
=Nv= Q mO  
+,{Wcb  
/* 98b9%Z'2f  
**Utility.java Z+`{JE#  
*/ 5b{yA~ty  
package NetFox; >2/wzsW  
WO+?gu  
#<WyId(  
public class Utility { 5u u2 _B_L  
3wa<,^kqy  
r:8]\RU  
public Utility() 5.C[)`_  
{ P98X[0&  
-UD~>s  
NZ%~n:/V#  
} ?V\9,BTb)  
0,L$x*Nj5  
//线程睡眠 g qJEJ~  
public static void sleep(int nSecond) Cr V2 V)|G  
{ ~\@<8@N2a6  
try{ :}3qZX  
Thread.sleep(nSecond); iuU3*yyn  
} wE8a4.  
catch(Exception e) /F8\%l+  
{ xJF6l!`  
e.printStackTrace (); W:+2We@  
} 0imqj7L  
} _'v }=:X  
u=v%7c2Mx}  
//日志 Ae{4AZ  
public static void log(String sMsg) H>X>5_{}  
{ Z.Y;[Y  
System.err.println(sMsg); {KpH|i  
} "ZJ1`R=Mj  
J:mu%N`  
(fk, 80  
public static void log(int sMsg) 2 Zjb/  
{ G4iLCcjY  
System.err.println(sMsg); n%MYX'0  
} !EmR(x  
} \dxW44sM  
pD}VB6=  
_G}CD|Kx  
/* 5(MZ%-~l  
**TestMethod.java [;V1y`/K1  
*/ Er)_[^) HG  
package NetFox; [nPzh Xs  
FOUs= E[  
<*(UvOQuX  
public class TestMethod { oN6*WN tJ  
fFTvf0j  
B,m$ur#$  
public TestMethod() }2!5#/^~  
{ ///xx/weblogic60b2_win.exe 3EW f|6RI  
try{ UN .[,%<s  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 2Fp]S a  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); d`],l\o C  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {+UNjKQC  
fileFetch.start(); 4pTu P /  
} _]~ht H  
catch(Exception e){e.printStackTrace ();} 84oW  
o|*|  
A@  
} WJh;p: q[  
!wR{Y[Yu  
MCrO]N($b  
public static void main(String[] args) i>if93mpj  
{ I.\f0I'.  
new TestMethod(); 2}#wd J`  
} feq6!k7  
} kx:lk+Tx  
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
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八