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http断点续传简单实现(java)

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/* 8taaBM`:  
**SiteFileFetch.java fd)}I23Q'  
*/ I/'jRM  
package NetFox; 5B@&]-'~  
import java.io.*; G-;pMFP(?  
import java.net.*; s=KA(4p  
fC81(5   
5SK.R;mn  
public class SiteFileFetch extends Thread { -$mzzYH  
U :IQWlC  
jdoI)J@9H  
SiteInfoBean siteInfoBean = null; //文件信息Bean `Y'}\>.#  
long[] nStartPos; //开始位置 $aVcWz %  
long[] nEndPos; //结束位置 UHxXa*HyI  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Pu}2%P)p  
long nFileLength; //文件长度 `[`eg<xj  
boolean bFirst = true; //是否第一次取文件 b9"Q.*c<Z^  
boolean bStop = false; //停止标志 ousoG$Pc  
File tmpFile; //文件下载的临时信息 Q4Cw{2r  
DataOutputStream output; //输出到文件的输出流 `VS/ Xyp  
"\e9Y<  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) XLOk+Fn  
public SiteFileFetch(SiteInfoBean bean) throws IOException T T29 LC@  
{ %3~jg  
siteInfoBean = bean; N b+zP[C  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); :@n e29,}  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /)v X|qtIY  
if(tmpFile.exists ()) -1U]@s  
{  okfhd{9  
bFirst = false; gI T"nG=a4  
read_nPos(); |qZ4h7wL  
} Aw >DZ2  
else !$&K~>`  
{ U?.VY@  
nStartPos = new long[bean.getNSplitter()]; n.Ekpq\  
nEndPos = new long[bean.getNSplitter()]; ,@GI3bl  
} AC 3 ;i  
t&-7AjS5  
[,l BY-Kz+  
y5oiH  
} MF>?! !  
C/lp Se  
H!7/U_AH  
public void run() T} U`?s`)  
{ 6&h,eQ!  
//获得文件长度 Vbz$dpT  
//分割文件 *n}{ )Ef  
//实例FileSplitterFetch >a]{q^0  
//启动FileSplitterFetch线程  X&(1DE  
//等待子线程返回 %m{h1UQQ +  
try{ WG1x:,-  
if(bFirst) !WAbO(l  
{ lKwIlp  
nFileLength = getFileSize(); OBu$T&  
if(nFileLength == -1) $S3C_..  
{ _AK-AY  
System.err.println("File Length is not known!"); (AV j_Cw  
} UDGVq S!,E  
else if(nFileLength == -2) gh3_})8c  
{ na>UFw7>*  
System.err.println("File is not access!"); 02?y%  
} Sh=z  
else n{=vP`V_  
{ lP0'Zg(  
for(int i=0;i<nStartPos.length;i++) +.gZILw  
{ /2 WGo-  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,uK }$l  
} b m`x  
for(int i=0;i<nEndPos.length-1;i++) X8y&|uH  
{ }zj_Pp  
nEndPos = nStartPos[i+1]; ?3"lI,!0  
} qK,rT*5=  
nEndPos[nEndPos.length-1] = nFileLength; Me2%X>;  
} ?>DN7je  
} {0QNqjue  
mM!Gomp  
4Bs '5@  
//启动子线程 CKy' 8I9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8)/d8@  
for(int i=0;i<nStartPos.length;i++) J?LetyDNr]  
{ O_*%_S}F&  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3Vs8"BFjz  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }~y i6!w'  
nStartPos,nEndPos,i); M;-PrJdyt  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7S}NV7  
fileSplitterFetch.start(); g-Vxl|hR  
} d3<7t  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), sA#}0>`3S  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^#KkO3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", _?CyKk\I  
nEndPos = " + nFileLength); >-0Rq[)  
// fileSplitterFetch[nPos.length-1].start(); 0EKi?vP@y7  
k`_sKr]9  
;M1#M:  
//等待子线程结束 +9<"Y6  
//int count = 0; }&F|u0@b  
//是否结束while循环 mA@FJK_  
boolean breakWhile = false; W2&o'(P\  
 6g576  
n#|ljC  
while(!bStop) _<qe= hie!  
{ #~BsI/m  
write_nPos(); =+DfIO  
Utility.sleep(500); #p*D.We  
breakWhile = true; +DU^"q=  
=;ClOy9  
i}[cq_wJ  
for(int i=0;i<nStartPos.length;i++) j4k\5~yzS  
{ gF# HNv  
if(!fileSplitterFetch.bDownOver) e#!%:M;4P  
{ 3K!(/,`  
breakWhile = false; jmPnUn  
break; |Bz1u|uc  
} c#( Hh{0  
} -Aaim`06bv  
if(breakWhile) vhIZkz!9  
break; m Q4(<,F  
G5vp(%j  
FUzN }"\1  
//count++; JlR$"GU  
//if(count>4) ~@=(#tO.  
// siteStop(); }IEwGoDwNs  
} =h0vdi%{  
%;_94!(hC  
Xdh2  
System.err.println("文件下载结束!"); ^F,sV*  
} 2. '` mGu  
catch(Exception e){e.printStackTrace ();} B>.x@(}V~  
} & OYo  
ORuC("  
K*I!:1;3N  
//获得文件长度 UE8j8U'L  
public long getFileSize() @GUlw[vi  
{ j 5}'*  
int nFileLength = -1; 4Hy/K^Ci  
try{ 5(>SFxz"t  
URL url = new URL(siteInfoBean.getSSiteURL()); O,6Wdw3+-3  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); MH=7(15R  
httpConnection.setRequestProperty("User-Agent","NetFox"); VWq]w5oQO  
' _d4[Olu  
o1`\*]A7J  
int responseCode=httpConnection.getResponseCode(); I+=+ ,iXhB  
if(responseCode>=400) p<1y$=zS  
{ A:y HClmn  
processErrorCode(responseCode); 3P@D!lV&K  
return -2; //-2 represent access is error 5skxixG  
} [?%q,>F  
>)F "lR:o  
zD)/QFILy  
String sHeader; ]Hp>~Zvbb  
XeX\u3<D  
n{u\t+f  
for(int i=1;;i++) &AN1xcx\  
{ B (Ps/  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cbN;Kv?ak}  
//Utility.log(in.readLine()); Mg #yl\v  
sHeader=httpConnection.getHeaderFieldKey(i); >-w(P/  
if(sHeader!=null) $=iw<B r  
{ _%q~K (::  
if(sHeader.equals("Content-Length")) jp_|pC'  
{ =Ox}WrU~  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #x;,RPw5  
break;  />Q}0H g  
} aaP_^m O  
} wBcoh~ (y  
else q3AqU?f  
break;  0j_kK  
} c/Xg ARCO  
} h2 KI  
catch(IOException e){e.printStackTrace ();} 7:,f|>  
catch(Exception e){e.printStackTrace ();} 9w$m\nV  
=:aJZ[UU<2  
*,mI=1  
Utility.log(nFileLength); AHRJ7l;a  
gVrQAcJj  
J$Z=`=] t+  
return nFileLength; 2]1u0-M5L  
} }x?F53I)  
h%:rJ_#Zl  
4;fuS_(X  
//保存下载信息(文件指针位置) L RVcf  
private void write_nPos() l%T4:p4e  
{ U@M3.[jw  
try{ Hs*["zFc  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T]\c2U  
output.writeInt(nStartPos.length); TP"cEfs x  
for(int i=0;i<nStartPos.length;i++) I]^>>>p$  
{ L8 L1_  
// output.writeLong(nPos); wqhktgG  
output.writeLong(fileSplitterFetch.nStartPos); ,Klv[_x7  
output.writeLong(fileSplitterFetch.nEndPos); =}vT>b  
} "|h%Uy?XY  
output.close(); - 8p!,+Dk  
} nq)F$@  
catch(IOException e){e.printStackTrace ();} z@yTkH_  
catch(Exception e){e.printStackTrace ();} [ n7>g   
} $P=C7;  
*!%lBt{2  
U}LW8886  
//读取保存的下载信息(文件指针位置) =eDIvNps  
private void read_nPos() * :O"R  
{ `&M,B=E  
try{ sU"%,Q5  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H_X^)\oJ  
int nCount = input.readInt(); 9<6q(]U  
nStartPos = new long[nCount]; ovdJ[bO  
nEndPos = new long[nCount]; hbJ>GSoZ,  
for(int i=0;i<nStartPos.length;i++) z5kAf~A  
{ $iu[-my_  
nStartPos = input.readLong(); .!x&d4;,q  
nEndPos = input.readLong(); fbNzRXw  
} X` zWw_i  
input.close(); gv''A"  
} unLhI0XW  
catch(IOException e){e.printStackTrace ();} TIWR[r1!  
catch(Exception e){e.printStackTrace ();} (k?H T'3)  
} G3~`]qf  
d ~Z\%4  
b6bs .  
private void processErrorCode(int nErrorCode) yOq@w!xz  
{ wT4@X[5$  
System.err.println("Error Code : " + nErrorCode); E5w;75,  
} 9af.t  
qI+2,6 sGI  
J;C:nE|V  
//停止文件下载 1u 9hA~rj  
public void siteStop() '+`[)w  
{ iRzFA!wH  
bStop = true; <s9?9^!!V^  
for(int i=0;i<nStartPos.length;i++) cJ;Nh>ey  
fileSplitterFetch.splitterStop(); ~SnUnNDm`  
j*jUcD *  
Z!)~?<gcq:  
} ilA45@  
} 0NXH449I=  
//负责部分文件的抓取 5 % 2A[B  
**FileSplitterFetch.java }yz>(Pq  
*/ # ]7Lieh[5  
package NetFox; *\sPHz.  
;2p+i/sVj  
D|N4X`T`  
import java.io.*;  .Q{RT p  
import java.net.*; Bqq=2lj  
an"&'D}U  
Zh=a rlk  
public class FileSplitterFetch extends Thread { 2 T!Tiu  
9} (w*>_L  
558P"w0"X  
String sURL; //File URL 9a}9cMJ^"  
long nStartPos; //File Snippet Start Position <$A,Ex94  
long nEndPos; //File Snippet End Position c0qp-=^&.  
int nThreadID; //Thread's ID fpD$%.y'J  
boolean bDownOver = false; //Downing is over 5 4gr'qvr  
boolean bStop = false; //Stop identical -U d^\Yy  
FileAccessI fileAccessI = null; //File Access interface K3T.l#d'L  
6l#x1o;  
, NSf  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Mo,&h?VOM?  
{ U1[)eD`  
this.sURL = sURL; /wV|;D^ )  
this.nStartPos = nStart; 3Q=^&o0fl  
this.nEndPos = nEnd; l":W@R  
nThreadID = id; Ri.tA  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mj~:MCC  
} LeKovt%  
H@Dpht>[  
"Ms;sdjg}&  
public void run() 0 j.K?]f)h  
{ E}@C4pS  
while(nStartPos < nEndPos && !bStop) RkF#NCnL;  
{ >STtX6h  
eS`VI+=@0  
]A*}Dem*5  
try{ OtG\Uw8  
URL url = new URL(sURL); rE3dHJN;  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); P@{ x@9kI  
httpConnection.setRequestProperty("User-Agent","NetFox"); UUah5$Iy  
String sProperty = "bytes="+nStartPos+"-"; i0vm00oT  
httpConnection.setRequestProperty("RANGE",sProperty); ag-A}k>v  
Utility.log(sProperty); X8 nos  
dzf2`@8#  
eqbN_$>  
InputStream input = httpConnection.getInputStream(); Cp8=8N(Xb  
//logResponseHead(httpConnection); Nwvlv{k'  
RB5SK#z  
v pI9TG  
byte[] b = new byte[1024]; XYEwn_Y  
int nRead; IG781:,/  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fab'\|Y   
{ ,X4e?$7g  
nStartPos += fileAccessI.write(b,0,nRead); jvzioFCt  
//if(nThreadID == 1) #36Q O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g^AQBF  
} 34@[ZKJ5  
8v4}h9*F"7  
);5o13h2  
Utility.log("Thread " + nThreadID + " is over!"); >4:d)  
bDownOver = true; ~>2uRjvkwB  
//nPos = fileAccessI.write (b,0,nRead); k3~9;Z  
} ]v+<K63@T  
catch(Exception e){e.printStackTrace ();} U7r8FLl  
} nbi7r cT  
} {o=?@$6C  
NGx3f3 9  
| f#wbw  
//打印回应的头信息 8nz({Mb9Z  
public void logResponseHead(HttpURLConnection con) U{U"%XdO  
{ Q;M\fBQO}&  
for(int i=1;;i++) ?,} u6tH  
{ $3-v W{<  
String header=con.getHeaderFieldKey(i); +>$]leqa  
if(header!=null) }F`|_8L*v)  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oMh$:jR$  
Utility.log(header+" : "+con.getHeaderField(header)); 0RUk^  
else 6Rc=!_v^  
break; Knq 9 "k  
} 'h>uR|  
} 9t`;~)o  
$TQhr#C]  
&!!*xv-z  
public void splitterStop() LQ+/|_(.  
{ ?jx]%n fV  
bStop = true; VF]AH}H8I  
} nm'l}/Ug  
dC11kq qj  
_z\/{  
} /d`"WK,  
^^y eC|~N:  
fgLjF,Y  
/* G7Nw}cVJ)  
**FileAccess.java / 3A6xPOg  
*//文件访问(定位,写) *Gsj pNr-  
package NetFox; +y7z>Fwl  
import java.io.*; ua\t5M5  
kaG/8G(  
X>q`F;W  
public class FileAccessI implements Serializable{ gI+8J.AG=  
FG?Mc'r&  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fi+}hGj(r  
RandomAccessFile oSavedFile; .[|UNg  
long nPos; SZykG[  
iD^,O)b  
Jt~Ivn,  
public FileAccessI() throws IOException hI[} -  
{ 3jmo[<p*x  
this("",0); .@1+}0  
} -m@o\9Ic  
h`[$ Bp  
,75)  
public FileAccessI(String sName,long nPos) throws IOException *~rj!N?;  
{ Q eeV<  
oSavedFile = new RandomAccessFile(sName,"rw"); "wUIsuG/p  
this.nPos = nPos; 7"(!]+BW!O  
oSavedFile.seek(nPos); .)Tj}Im2p  
} rhv~H"qzW  
3Ax'v|&Hg  
]#!uke Q  
public synchronized int write(byte[] b,int nStart,int nLen) ((y|?Z$  
{ kA :Y^2X'  
int n = -1; Fs+ tcr/\[  
try{ O zAIz+`  
oSavedFile.write(b,nStart,nLen); 4kOO3[r  
n = nLen; #-{<d% qk  
} U,P_bz*)  
catch(IOException e) k.J%rRneN  
{ [4)Oi-_Y>  
e.printStackTrace (); UwN Vvo  
} `L1,JE` q  
P_bB{~$4  
z8kO)'  
return n; 3%WB?k c  
} Gnc`CyN:H  
Q|y }mC/  
Psb !Z(  
} Pt]>AW;i  
Zxk~X}K\P  
ffKgVQux  
/* s%[F,hQRk  
**SiteInfoBean.java |/.J{=E0K  
*/ ]a3$hAcj6"  
package NetFox; AFLtgoXn:  
?K1B^M=8  
cNll??j  
public class SiteInfoBean {  tV}!_  
h~dQ5%  
)p& g!qA  
private String sSiteURL; //Site's URL ^FCXcn9  
private String sFilePath; //Saved File's Path :X2_#qW#C  
private String sFileName; //Saved File's Name }{0}$#z u  
private int nSplitter; //Count of Splited Downloading File mz?<t/$U  
So%X(, |  
fN vQ.;  
public SiteInfoBean() RTtKf i}  
{//nSplitter的缺省值为5 C{)1#<`  
//default value of nSplitter is 5 C6+ 5G-Z  
this("","","",5); O\}C`CiC  
} YAi-eL67l  
Cq5.gkS<  
Mf5j'n  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kHM Jh~  
{ ]m1fo'  
sSiteURL= sURL; 5Cf!NNV  
sFilePath = sPath; Y,]Lk<Hm3  
sFileName = sName; 3:nhZN/95T  
this.nSplitter = nSpiltter; s 6Wp"V(  
BR|!ya+_2  
u=`H n-(  
} .1QGNW  
,0'G HQWz$  
j cd<'\;  
public String getSSiteURL() pwSgFc$z  
{ iUkUo x  
return sSiteURL; 5(;Y&?k  
} Ou[K7-m%&  
p.8bX  
79DNNj~  
public void setSSiteURL(String value) ixTjXl2g  
{ jCd]ENl+_  
sSiteURL = value; ]3r}>/2(  
} .ARYCTyG  
F`=p/IAJK  
0d2P   
public String getSFilePath() (3e.q'  
{ 4:MvC^X~z  
return sFilePath; Jb,54uN  
} .G/Rh92  
vG|!d+  
z']6C9m}  
public void setSFilePath(String value) xj5TnE9^  
{ KGt:  
sFilePath = value; KpN]9d   
} X G#?fr}L  
&YFe"C  
>N&{DJmD  
public String getSFileName() #.8v[TkKq  
{  lKbWQ>  
return sFileName; )x-b+SC  
} s,R:D).  
T CT8OU|  
74^v('-2  
public void setSFileName(String value) Iv6 lE:)  
{ FDo PW~+[  
sFileName = value; txEN7!  
} Z% +$<J  
4*_jGw  
lHiWzt u  
public int getNSplitter() ~[H8R|j "  
{ .Ys e/oEo  
return nSplitter; 2EgvS!"  
} @@R Mm$  
]*dYX=6  
s|IBX0^@  
public void setNSplitter(int nCount) OvH:3 "Sdy  
{ EBhdP  
nSplitter = nCount; # epP~J_f  
} wv~:^v'  
} @Y0ZW't  
xMbgBx4+  
. !1[I{KU  
/* 3f =ZNJ>  
**Utility.java sY<UJlDKT  
*/ ~[=<O s  
package NetFox; S1|5+PPs  
$f@YQN=  
?N4FB*x  
public class Utility { .!q_jl%U  
coCT]<  
Na@bXcz)  
public Utility() Z?P^Y%ls  
{ jCY~Wc  
c5p,~z_Dtu  
(wj:Gc  
} ?}`- ?JB1  
c0wLc,)G  
//线程睡眠 !'_7MM  
public static void sleep(int nSecond) !B`z|#  
{ F{mUxo#T  
try{ ;R= n<=Axa  
Thread.sleep(nSecond); R_!'=0}V  
} l/k-` LeW  
catch(Exception e) )qx;/=D  
{ G]h_z|$K  
e.printStackTrace (); B=Kr J{&!  
} $SQ$2\iC  
} [IHo ~   
2 G.y.#W  
//日志 _DxHJl  
public static void log(String sMsg) cs6oD!h  
{ 5mam WPw  
System.err.println(sMsg); L#S W!  
} ?|,:;^2l1  
GZO:lDdA  
fXWy9 #M  
public static void log(int sMsg) %N Q mV_1  
{ k'r}@-X  
System.err.println(sMsg); yeyDB>#Va.  
} h: yJ  
} f?d5Ltg   
=]%,&Se  
/KvJjt'8  
/* _Q:z -si  
**TestMethod.java OUWK  
*/ brp3xgQ`]  
package NetFox; DpggZ|J  
)bM,>x  
z5gVP8*z5  
public class TestMethod { UvGxA[~2+  
7:B/ ?E  
3;buC|ky  
public TestMethod() 4Q!A w  
{ ///xx/weblogic60b2_win.exe m 3UK`~ji  
try{ M|c_P)7ym  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uZ8-?  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Xz@#,F:@  
SiteFileFetch fileFetch = new SiteFileFetch(bean); u7mPp3ZYK  
fileFetch.start(); "BsK' yo.  
} ^g4Gw6q 6  
catch(Exception e){e.printStackTrace ();} PVg<Ovi^d  
' pgP QM<  
ZBDF>u@  
} t+ w{uwEY  
a X1b(h2  
u<8b5An;  
public static void main(String[] args) dnomnY(*<  
{ *%/O (ohs@  
new TestMethod(); zG$5g^J  
} t Cb34Wpf  
} n UmyPQ~  
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