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http断点续传简单实现(java)

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/* K0'= O  
**SiteFileFetch.java V M{Sng  
*/ dh-?_|"  
package NetFox; S[5OTwa8L  
import java.io.*; q5G`N>"V  
import java.net.*; Y1-=H)G  
3S=$ng  
W!R7D%nX  
public class SiteFileFetch extends Thread { .$U=ng j\t  
%% +@s   
h )% e  
SiteInfoBean siteInfoBean = null; //文件信息Bean -_^#7]  
long[] nStartPos; //开始位置 Y;1s=B9  
long[] nEndPos; //结束位置 ys- w0H  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ">v- CSHY  
long nFileLength; //文件长度 o\N^Uu  
boolean bFirst = true; //是否第一次取文件 E4N"|u|   
boolean bStop = false; //停止标志 SNrX(V::z  
File tmpFile; //文件下载的临时信息 gHox>r6.A  
DataOutputStream output; //输出到文件的输出流 cXIuGvE&=  
f#&@Vl(i&  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) E^C [G)7n  
public SiteFileFetch(SiteInfoBean bean) throws IOException `1i\8s&O6@  
{ <~hx ~"c  
siteInfoBean = bean; _+ERX[i  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); #}+_Hy  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ?.g="{5X  
if(tmpFile.exists ()) *]>~lO1  
{ :4x&B^,53  
bFirst = false; ow4|GLU^;  
read_nPos(); %4x,^ K]  
} Ij?Qs{V  
else l9+)h }  
{ X&gXhr#dL\  
nStartPos = new long[bean.getNSplitter()]; xA>3]<O  
nEndPos = new long[bean.getNSplitter()]; ;%mdSaf  
} }*|aVBvU  
r"W<1H u  
)&[Zw{6P  
wpf  
} \=j|ju3  
#&Fd16ov  
LM*m> n*  
public void run() :Tdl84   
{ ,!bcm  
//获得文件长度 asL!@YE  
//分割文件 >a)6GZ@  
//实例FileSplitterFetch JpZ3T~Wrf  
//启动FileSplitterFetch线程 0IxHB|^$  
//等待子线程返回 SD.c 9  
try{ ]htx9ds=  
if(bFirst) \79aG3MyK  
{ &`}ACTY'P  
nFileLength = getFileSize(); /rnP/X)T  
if(nFileLength == -1) R_duPaWc@  
{ fO}Y$y\q  
System.err.println("File Length is not known!"); oR}'I  
} vFK!LeF%  
else if(nFileLength == -2) 2$O6%0  
{ :9W)CwZ)V  
System.err.println("File is not access!"); Wl{wY,u  
} kj@m5`G  
else QuBaG<  
{ zvKypx  
for(int i=0;i<nStartPos.length;i++) z<u@::  
{ mU;\,96#  
nStartPos = (long)(i*(nFileLength/nStartPos.length));  V/t-  
} *?!A  
for(int i=0;i<nEndPos.length-1;i++) _))--+cL  
{ Z`yW2ON$'  
nEndPos = nStartPos[i+1]; *W<|5<<u@  
} Za'}26  
nEndPos[nEndPos.length-1] = nFileLength; \SA$:^zO  
} T;pe7"  
} Zrp9`~_g<!  
E|ZLz~  
%5/h;4   
//启动子线程 j12khp?  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wa'm]J  
for(int i=0;i<nStartPos.length;i++) 'cf8VD  
{ '+iqbcUd,  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .!Os'Y9[,  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G;;iGN  
nStartPos,nEndPos,i); 4fau 9bW  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |r/4 ({n  
fileSplitterFetch.start(); j6&7tK,  
} cp 5  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i]IZ0.?Y  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bEl)/z*gy/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q6zKyOE  
nEndPos = " + nFileLength); CDGN}Q2_  
// fileSplitterFetch[nPos.length-1].start(); ?OdJ t  
"kkZK=}Nv  
?Q/9aqHe;  
//等待子线程结束 0 hS(9y40  
//int count = 0; r&D&xsbQ  
//是否结束while循环 Gu\lV c  
boolean breakWhile = false; QW6\~l 4  
6Ej@;]^^-  
z=a{;1A  
while(!bStop) 2w67 >w\  
{ 3QD##Wr^  
write_nPos(); e]u3[ao  
Utility.sleep(500); QVQ?a&HYS  
breakWhile = true; q /^&si  
28d=-s=[  
aDE)Nf}  
for(int i=0;i<nStartPos.length;i++) dS"%( ?o  
{ ntEf-x<  
if(!fileSplitterFetch.bDownOver) UU 2 =W  
{ }~$96|J  
breakWhile = false; N TL`9b  
break; ccJ!N  
} y3pr(w9A  
} 16n8[U!  
if(breakWhile) Qh@A7N/L  
break; O)9{qU:[b  
VH5Vg We  
Dv[ 35[Yh  
//count++; 3bPF+(`J  
//if(count>4) $_NP4V8|z/  
// siteStop(); <e7  
} [";<YR7iRN  
$.-\2;U  
1U< g  
System.err.println("文件下载结束!"); "+:~#&r  
} \hFIg3  
catch(Exception e){e.printStackTrace ();} >$p|W~x  
} cQldBc  
y}!}*Qj+/  
BjIKs~CT  
//获得文件长度 |HMpVT-;j  
public long getFileSize() Z4@GcdZ  
{ $r87]y!  
int nFileLength = -1; E0a &1j  
try{ s6J`i&uu  
URL url = new URL(siteInfoBean.getSSiteURL()); 8^%Nl `_2B  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a5# B&|#q  
httpConnection.setRequestProperty("User-Agent","NetFox"); '{xPdN  
$E]W U?U  
Wf>scl `s  
int responseCode=httpConnection.getResponseCode(); h$~ \to$C  
if(responseCode>=400) TEi~X 2u  
{ ]M5w!O!  
processErrorCode(responseCode); `t~Zkb4>  
return -2; //-2 represent access is error ',P E25Z  
} =g+Rk+jn  
#DFfySH)A  
OFe?T\dQn  
String sHeader; /htM/pR  
o7;#B)jWS  
jsOid5bs  
for(int i=1;;i++) yxz"9PE/P  
{ f]Q`8nU  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PhOtSml0  
//Utility.log(in.readLine()); y,QJy=?  
sHeader=httpConnection.getHeaderFieldKey(i); :gJ?3LwTf  
if(sHeader!=null) t\%gP@?  
{ /"%(i#<)xs  
if(sHeader.equals("Content-Length")) x[5uz))  
{ yq2pg8%  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kL1StF#p  
break; vMB`TpZ  
} Wy`ve~y  
} lboi\GP|  
else rW(<[2vg  
break; V O= o)H\  
}  YXr"  
} ht 1d[  
catch(IOException e){e.printStackTrace ();} U4*Q;A#  
catch(Exception e){e.printStackTrace ();} ^*=.Vuqy  
w`$M}oX(  
A%$ZB9#zQ  
Utility.log(nFileLength); fyE#8h_>4  
s35`{PR  
swh8-_[c/  
return nFileLength; 8A ;)5!  
} efu'PfZ`&  
n$O[yRMI[  
E'O[E=  
//保存下载信息(文件指针位置) nF!6  
private void write_nPos() bYKe5y=  
{ ~!& "b1  
try{ }[gk9uM_7  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ecRY,MN  
output.writeInt(nStartPos.length); Ghb Jty`  
for(int i=0;i<nStartPos.length;i++) Z>si%Npm\  
{ O<o>/HH$  
// output.writeLong(nPos); ~d072qUos  
output.writeLong(fileSplitterFetch.nStartPos); BrO" _  
output.writeLong(fileSplitterFetch.nEndPos); Dxlpo! ?#  
} gx',~  
output.close(); p2/Pj)2  
} y]e[fZ`L  
catch(IOException e){e.printStackTrace ();} R ]! [h  
catch(Exception e){e.printStackTrace ();} :7 P/ZC%  
} RU_wr<  
9_  
/ !@@  
//读取保存的下载信息(文件指针位置) Adma~]T9  
private void read_nPos() ^L@2%}6b`  
{ e: aa  
try{ \_w>I_=F  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XDdF7i}  
int nCount = input.readInt(); J )DFH~p  
nStartPos = new long[nCount]; 74p=uQ  
nEndPos = new long[nCount]; DQy<!Wb+  
for(int i=0;i<nStartPos.length;i++) W#.+C6/  
{ 4,]z  
nStartPos = input.readLong(); ,&5\`  
nEndPos = input.readLong(); +338z<'Z!  
} 4{rqGC /  
input.close(); !F|#TETrt  
} Sbp].3^j  
catch(IOException e){e.printStackTrace ();} W:gpcR]>  
catch(Exception e){e.printStackTrace ();} CVy\']  
} nde_%d$  
.*Mp+Q}^  
~stJO])a  
private void processErrorCode(int nErrorCode) <Cbi5DtR  
{ NrK.DY4  
System.err.println("Error Code : " + nErrorCode); Y*Ra!]62  
} ni gn" r  
45aUz@  
MoX~ZewWR  
//停止文件下载 -+ha4JOB  
public void siteStop() \~!!h.xR  
{ TF1,7Qd  
bStop = true; ]~K&b96(  
for(int i=0;i<nStartPos.length;i++) ~EL3I  
fileSplitterFetch.splitterStop(); G=ly .  
=G,wR'M  
k:QeZn(  
} <9bfX 91  
} l{o,"P"  
//负责部分文件的抓取 LpYG!Kl  
**FileSplitterFetch.java R9z:K_d,  
*/ NZoNsNu*C.  
package NetFox; 6D&{+;  
/f}!G  
je`Ysben  
import java.io.*; JJZu%9~[  
import java.net.*; >2t.7UhDI  
N xW Dw  
ki6L t  
public class FileSplitterFetch extends Thread { YEPQ/Pc  
zo| '  
E#!tXO&,  
String sURL; //File URL kfV}ta'^S  
long nStartPos; //File Snippet Start Position .<Rw16O  
long nEndPos; //File Snippet End Position qeUT]* w  
int nThreadID; //Thread's ID QJ,[K _  
boolean bDownOver = false; //Downing is over 5(=5GkE)>  
boolean bStop = false; //Stop identical 9,wD  
FileAccessI fileAccessI = null; //File Access interface 4^Y{ BS fF  
e~U]yg5X-  
ZQk!Ia7  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M '#a.z%  
{ TT@ U_^o  
this.sURL = sURL; _1,hO?TK  
this.nStartPos = nStart; +6`+Q2qi  
this.nEndPos = nEnd; fg)VO6Wo&  
nThreadID = id; PS}'LhZ  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KcvstC`  
} l+A)MJd oj  
;l %$-/%  
?Gl]O3@3  
public void run() ~NMx:PP  
{ )GYnQoV4  
while(nStartPos < nEndPos && !bStop) @tvz9N  
{ g&*,j+$ }  
awv$ }EFo  
`FGYc  
try{ s(Bcw`'#  
URL url = new URL(sURL); )Yu  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jNvDE}'  
httpConnection.setRequestProperty("User-Agent","NetFox"); ZXIw^!8@/  
String sProperty = "bytes="+nStartPos+"-"; oo\7\b#Jx  
httpConnection.setRequestProperty("RANGE",sProperty); @V&c=8) 8  
Utility.log(sProperty); g\% Z+Dc  
* '_(.Z:  
'^.`mT'P  
InputStream input = httpConnection.getInputStream(); 9Vru,7g  
//logResponseHead(httpConnection); 5%%e$o+  
4`B3Kt`o  
"ze-Mb  
byte[] b = new byte[1024]; } J[Z)u  
int nRead; 4_`(c1oA  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UCt}\IJ  
{ /go|r '  
nStartPos += fileAccessI.write(b,0,nRead); )qRH?Hsb7  
//if(nThreadID == 1) Vel}lQD  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %s! |,Cu  
} `Gj(>z*  
dEZUK vo  
q{ [!" ,  
Utility.log("Thread " + nThreadID + " is over!"); ]|-sZ<?<i  
bDownOver = true; '451H3LC0  
//nPos = fileAccessI.write (b,0,nRead); fX.1=BjXi  
}  k^Q.lb {  
catch(Exception e){e.printStackTrace ();} 4*ZY#7h  
} .ht-*  
} E<jW; trt_  
:sQ>oNnz  
_U_O0@xi  
//打印回应的头信息 !Ii[`H  
public void logResponseHead(HttpURLConnection con) hvGD`  
{ 31~nay15  
for(int i=1;;i++) 9Pb6Z}  
{ L#",.x  
String header=con.getHeaderFieldKey(i); 35Yf,@VO  
if(header!=null) nwp(% fBo  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wFX9F3m  
Utility.log(header+" : "+con.getHeaderField(header)); Gl@{y (  
else &7i&"TNptP  
break; 2t4\L3  
} Mf2F LrAh  
} E.Q]X]q  
|AH>EXhv  
:KgH7s}  
public void splitterStop() DXo]O}VF  
{ jsQHg2Vd  
bStop = true; z %Bzf~N9  
} @c-  
<PVwf`W.  
| UlG@Mn  
} '4nJ*Xa  
D#AqZS>B  
b[GhI+_  
/* lLp,sNAj  
**FileAccess.java :r@t'  
*//文件访问(定位,写) `% QvCAR  
package NetFox; -72EXO=|  
import java.io.*; vQ L$.A3>  
PcBD;[cn  
fZezDm(Q  
public class FileAccessI implements Serializable{ 6Cz O ztn  
qVKdc*R-  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o K>(yC[  
RandomAccessFile oSavedFile; CxTmW5l  
long nPos; oNtoqYwH  
,sIC=V +  
@AF<Xp{  
public FileAccessI() throws IOException V^,eW!  
{ gfs;?vP  
this("",0); zGFD71=#  
} i84!x%|P  
MoE&)~0u&  
(c>g7d<>n  
public FileAccessI(String sName,long nPos) throws IOException l2LLM{B  
{ p]%di8&;N  
oSavedFile = new RandomAccessFile(sName,"rw"); +ID\u <?  
this.nPos = nPos; K Ax=C}9  
oSavedFile.seek(nPos); vjq2(I)u  
} )Xh}N  
o]~\u{o#.  
d)e mTXB(  
public synchronized int write(byte[] b,int nStart,int nLen) h7 E~I J  
{ g"Y _!)X  
int n = -1; <(q(5jG  
try{  ]'`E  
oSavedFile.write(b,nStart,nLen); PR Mg6  
n = nLen; &s='$a; 4  
} UWF \Vx*)b  
catch(IOException e) [Q0V5P~Q'  
{ v!8=B21  
e.printStackTrace (); {u/1ph-  
} Y@`uBB[  
U fyhd  
6,A|9UX=`  
return n; F?|Efpzow?  
} *m}8L%<HT  
X>Vc4n<}  
=w! ik9  
} ~x^y5[5{  
Hi A E9  
`^Vd*  
/* w.-x2Zg},  
**SiteInfoBean.java _"ciHYHBQ  
*/ cv aG[NF  
package NetFox; ;NR|Hi]  
A<ds+0  
uYMn VE"  
public class SiteInfoBean { Xj 1Oxm 42  
:YI5O/gsk?  
_6nAxm&x`%  
private String sSiteURL; //Site's URL u<Kowt<ci  
private String sFilePath; //Saved File's Path UPI- j#yc  
private String sFileName; //Saved File's Name "5&"Ij,/  
private int nSplitter; //Count of Splited Downloading File ^o{{kju  
/@F'f@;  
0+e=s0s.  
public SiteInfoBean() <NMJkl-r8r  
{//nSplitter的缺省值为5 v-tI`Qpb  
//default value of nSplitter is 5 H-PVV&r   
this("","","",5); n@8Y6+7i  
} 0&UG=q  
x ;|HT  
TKR#YJQ?K  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $<v4c5r]O  
{ dS ojq6M  
sSiteURL= sURL; 2%sZaM  
sFilePath = sPath; UZI:st   
sFileName = sName; o]q~sJVk6  
this.nSplitter = nSpiltter;  u]Ku96!  
6sBt6?_T  
F:!6B b C  
} B/wD~xC?x  
HG;;M6  
hOwb   
public String getSSiteURL() `(FjOd K  
{ gsbr8zwG,  
return sSiteURL; =&z+7Pe[  
} v>]g="5}8  
@G" nkB   
QN#"c  
public void setSSiteURL(String value) :)~l3:O  
{ .; F<X \_  
sSiteURL = value; lxyTh'  
} )8A.Wg4S;c  
LDr?'M!D  
e*2^  
public String getSFilePath() '2.ey33V  
{ 0]4X/u#N  
return sFilePath; ij$NTY=u  
} ubM1Qr  
ZaYiby@Ci  
g8Ex$,\,  
public void setSFilePath(String value) ,Z~`aHhr  
{ !T,<p    
sFilePath = value; x4I!f)8Q  
} tnJ7m8JmC  
O2Qmz=%  
MJ JC6:  
public String getSFileName() SaXt"Ju,AH  
{ EHwb?{  
return sFileName; klUV&O+=%  
} ^ 8}P_  
l zFiZx  
Wq A) V,E  
public void setSFileName(String value) K,g6y#1"  
{ M{J>yN  
sFileName = value; 9<u&27.  
} q-(~w!e  
ni/s/^  
6{I7)@>N   
public int getNSplitter() |8'}mjs.Q  
{ L<!h3n  
return nSplitter; b-_l&;NWg  
} AwZ@)0Wy  
$mPR)T  
nLm'a_  
public void setNSplitter(int nCount) ZWCsrV*;  
{ a fa\6]m  
nSplitter = nCount; *:CTIV5N0  
} !igPyhi,hl  
} @&m [w'tn  
NPH(v`  
v@{y}  
/* rN&fFI  
**Utility.java ^aB;Oo  
*/ [)I^v3]U  
package NetFox; S%\5"uGa  
+ywz@0nx  
jr`T6!\  
public class Utility { Z;uKnJh  
zeMV_rW~  
@ym:@<D  
public Utility() nk|(cyt)  
{ vFe=AY<Rt|  
<9]"p2  
2E-Kz?,:[  
} TgcCR:eL=  
1'hpg>U  
//线程睡眠 wo&IVy@s$  
public static void sleep(int nSecond) 5$U49j  
{ 0aY|:  
try{ :$G^TD/n  
Thread.sleep(nSecond); :rr<#F  
} zu}uW,XH-  
catch(Exception e) dzIBdth  
{ < dE7+w  
e.printStackTrace ();  c k;:84  
} 1O Ft}>1  
} ~aotV1"D  
#X)DFAtb  
//日志 9BakxmAc  
public static void log(String sMsg) ,O:4[M!$w  
{ W>' DQB  
System.err.println(sMsg); XI Mh<  
} 570ja7C:  
1Lf -  
iX?j"=!  
public static void log(int sMsg) .Yk}iHcW.  
{ 4M"'B A<  
System.err.println(sMsg); Ue9d0#9  
} |}77'w :  
} glch06  
bD v& ;Z  
I]HYqI  
/* Oyb9 ql^  
**TestMethod.java NkUY_rKPb  
*/ F42^Uoaz  
package NetFox; !IJ YaQ6z  
r`ftflNh(  
n 'ZPB  
public class TestMethod { &DQ_qOKD  
`V/kM0A5  
#IppjaPl8  
public TestMethod() 6<z#*`U1  
{ ///xx/weblogic60b2_win.exe -qSGa;PJ  
try{ HA c"&#pG  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XyB_8(/E  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6Lq8#{/]u  
SiteFileFetch fileFetch = new SiteFileFetch(bean); - .) f~#8  
fileFetch.start(); <e Y2}Ml  
} ~I")-2"B  
catch(Exception e){e.printStackTrace ();} h/5V~ :)  
ZXhNn<  
rE "FN~9P  
} <DMm [V{  
]Y,V)41gCE  
1^AQLOiRE1  
public static void main(String[] args) +^J&x>5  
{ `_DA!  
new TestMethod(); \HD:#a  
} Uv k:  
} |s#,^SJ0  
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