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http断点续传简单实现(java)

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/* !`S%l1[Z  
**SiteFileFetch.java Wg;TXs/  
*/ $vicHuX!  
package NetFox; QCY{D@7T  
import java.io.*; K]]r OF  
import java.net.*; nO7o7bc  
y&I|m  
X52jqXjg  
public class SiteFileFetch extends Thread { ;[\2/$-  
Gw\HL  
nQYS{`hk  
SiteInfoBean siteInfoBean = null; //文件信息Bean v'~nABYH  
long[] nStartPos; //开始位置 BU?MRcHC  
long[] nEndPos; //结束位置 U;A5-|C  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 7 V1k$S(  
long nFileLength; //文件长度 gm8Tm$fY  
boolean bFirst = true; //是否第一次取文件  $.]t1e7s  
boolean bStop = false; //停止标志 RxeRO2  
File tmpFile; //文件下载的临时信息 )A+j  
DataOutputStream output; //输出到文件的输出流 *9:6t6x  
vi.AzO  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) gkn/E}K#  
public SiteFileFetch(SiteInfoBean bean) throws IOException bb_jD^  
{ L$kAe1 V^m  
siteInfoBean = bean; 6V?&hq&t  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ->25$5#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); XGl13@=O  
if(tmpFile.exists ()) KI QBY!N+  
{ e/#&5ISk  
bFirst = false; _"Ke=v_5  
read_nPos(); <`p'6n79  
} =gv/9ce)3  
else cj_?*  
{ I;4CvoT  
nStartPos = new long[bean.getNSplitter()]; `1v!sSR0R  
nEndPos = new long[bean.getNSplitter()]; $aI MQ[(  
} O]LuL&=s y  
ZV^J5wYE  
Fmle|  
MifgRUe  
} ={0{X9t?'j  
A;nmua-Fv  
=5_F9nk-   
public void run() # i=^WN<V  
{ nMvIL2:3  
//获得文件长度 B148wh#r  
//分割文件 |.8=gS5  
//实例FileSplitterFetch KKXb,/  
//启动FileSplitterFetch线程 |]3);^0  
//等待子线程返回 Ln%_8yth  
try{ 10a*7 L  
if(bFirst) ~u& O  
{ m95$V&  
nFileLength = getFileSize(); Q&'Nr3H#tZ  
if(nFileLength == -1) qtwmTT)  
{ q5?mP6   
System.err.println("File Length is not known!"); rBPxGBd4  
} fw};.M  
else if(nFileLength == -2) *B}R4Y|g  
{ s;f u  
System.err.println("File is not access!"); |MrH@v7S  
} Ntrn("!  
else LZ]pyoi  
{ hQx e0Pdt  
for(int i=0;i<nStartPos.length;i++) P(+ar#,G  
{ #_|^C(]!  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); HON[{Oq  
} iDxgAV f*  
for(int i=0;i<nEndPos.length-1;i++) .7rsbZzs  
{ VQ 3&  
nEndPos = nStartPos[i+1]; o=2`N2AL  
} li XD2N  
nEndPos[nEndPos.length-1] = nFileLength; *4VP5]!  
} sjkl? _  
} 1T?%i  
LKY Q?  
"G)?  E|  
//启动子线程 AG0x)  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *Yjs$'_2  
for(int i=0;i<nStartPos.length;i++) [B<{3*R_  
{ ]F-6KeBc  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), raZRa*C;  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yYtki  
nStartPos,nEndPos,i); EwZt/r  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Di=6.gm[<  
fileSplitterFetch.start(); O]!DNN  
} Tj+WO6#V  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w2V E_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n_2 LkW<?  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $&C%C\(>D  
nEndPos = " + nFileLength); @V u[Tg}J  
// fileSplitterFetch[nPos.length-1].start(); `<Nc Y*  
M<7*\1  
HWZ*Htr  
//等待子线程结束 M$A!  
//int count = 0; |(g2fByDf  
//是否结束while循环 4D$E  
boolean breakWhile = false; Q+N @j]'  
Y" |U$  
w$HC!  
while(!bStop) <[~M|OL9q,  
{ IrM3Uh  
write_nPos(); gI{F"7fa=  
Utility.sleep(500); C`K/ai{4  
breakWhile = true; QKQy)g  
%LmB`DqZ  
GMI >$$<  
for(int i=0;i<nStartPos.length;i++) o LRio.u*  
{ BpE[9N  
if(!fileSplitterFetch.bDownOver) ?2c:|FD  
{ Iqv 5lo .  
breakWhile = false; D=]P9XDvb.  
break; |.yRo_  
} AU2Nmf?]%  
} CeemR>\t  
if(breakWhile) ~8E rl3=5{  
break; T]k@g_  
tO$M[P=b  
``D-pnKK  
//count++; ~Q\[b%>J  
//if(count>4) 8a1{x(\z.  
// siteStop(); 1's^W  
} S8t9Ms: k  
J)f?x T*  
=*N(8j>y  
System.err.println("文件下载结束!"); <#i'3TUR  
} @ZZ Lh=  
catch(Exception e){e.printStackTrace ();} sj2+|>  
} p};<l@  
mmti3Y  
l-rI|0D#  
//获得文件长度 I(|{/{P,  
public long getFileSize() &[xJfL  
{ NU"X*g-x^  
int nFileLength = -1; Zs)9O Ju  
try{ S7]cF5N  
URL url = new URL(siteInfoBean.getSSiteURL()); 0jMrL\>C  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ns{4BM6j  
httpConnection.setRequestProperty("User-Agent","NetFox"); 4BX*-t  
jkd8M;Jw  
N0NMRU]zT  
int responseCode=httpConnection.getResponseCode(); PT=%]o]  
if(responseCode>=400) HH+XEMP/g  
{ {Gy_QRsp,  
processErrorCode(responseCode); EhoR.  
return -2; //-2 represent access is error UlR7_   
} 2t%)d9r32  
Gl(,%~F9i  
7P]pk=mo  
String sHeader; Y|bGd_j  
F{S.f1Bsp  
`Jo}/c 5R  
for(int i=1;;i++) z> SCv;Q  
{ =Vfj#WL  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z]dc%>  
//Utility.log(in.readLine()); pVM;xxJ  
sHeader=httpConnection.getHeaderFieldKey(i); [iz  
if(sHeader!=null) ^;e`ZtcI  
{ /on p<u  
if(sHeader.equals("Content-Length")) Fwtwf{9I  
{ dBkB9nz  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z2r\aZ-d`  
break; `1dr$U  
} b`' ;`*AN+  
} Mmn[ol  
else Iq9+  
break; +4 dHaj6  
} p O.8>C%  
} ;6Z?O_zp4  
catch(IOException e){e.printStackTrace ();} SJfsFi?n  
catch(Exception e){e.printStackTrace ();} Al?XJ C B@  
ZWv$K0agu  
1=>$c   
Utility.log(nFileLength); 5 m:nh<)#  
?hO*~w;UU|  
E^s>S,U[y  
return nFileLength; Hmz[pTQ|87  
} *Z(qk`e.b  
1*5n}cU~  
fw5AZvE6$  
//保存下载信息(文件指针位置) s<{c?4T  
private void write_nPos() l[gL(p"W  
{ 5|Uub ,  
try{ F+X3CB,f  
output = new DataOutputStream(new FileOutputStream(tmpFile)); >2ct1_  
output.writeInt(nStartPos.length); c?|/c9f  
for(int i=0;i<nStartPos.length;i++) Q{RHW@_/  
{ @#p4QEQA  
// output.writeLong(nPos); ;:cM^LJ  
output.writeLong(fileSplitterFetch.nStartPos); d-4u*>  
output.writeLong(fileSplitterFetch.nEndPos); a&&EjI  
} *i|hcDk  
output.close(); W`KkuQ4cM  
} m{X;|-DK[  
catch(IOException e){e.printStackTrace ();}  W* YfyM  
catch(Exception e){e.printStackTrace ();} ;YB8X&H$  
} r&#q=R},p  
^T" A9uaG  
>Kx l+F  
//读取保存的下载信息(文件指针位置) K_xn>  
private void read_nPos() CZ @M~Si_  
{ oR~+s &c  
try{ SngV<J>zR  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0\/7[nwS  
int nCount = input.readInt(); /H)l\m +  
nStartPos = new long[nCount]; )K}b,X`($  
nEndPos = new long[nCount]; cWm.']  
for(int i=0;i<nStartPos.length;i++) ]uP {Sj  
{ i^=an?}/  
nStartPos = input.readLong(); f,$FrI,  
nEndPos = input.readLong(); %j'lWwi  
} #ws6z`mt  
input.close(); REa%kU  
} 79&Mc,69  
catch(IOException e){e.printStackTrace ();} 6rk/74gI,a  
catch(Exception e){e.printStackTrace ();} \]^|IViIQ  
} ,y^By_1wS  
,5q^/h  
Vi]D](^!  
private void processErrorCode(int nErrorCode) RD~QNj9,T  
{ z*FlZLHY  
System.err.println("Error Code : " + nErrorCode); b{(:'.  
} Q.nEY6B_  
~_K   
Dq\#:NnKvx  
//停止文件下载 WvR}c  
public void siteStop() P0W%30Dh  
{  X(bb1  
bStop = true; &Zov9o:gx  
for(int i=0;i<nStartPos.length;i++) :QN,T3i'/3  
fileSplitterFetch.splitterStop(); \4V'NTjB  
GU!|J71z  
aPWFb.JO4  
} [QeKT8  
} 7"M7N^  
//负责部分文件的抓取 }L@YLnc%  
**FileSplitterFetch.java E_$ ST3  
*/ X!&=S!}  
package NetFox; ;DGp7f#9  
,u$$w  
p<Zf,F}  
import java.io.*; rq$%  
import java.net.*; |ek*wo  
e&E*$G@.7  
VGTo$RH  
public class FileSplitterFetch extends Thread { b\}`L"  
sH6srwI  
e7<~[>g)  
String sURL; //File URL A=BpB}b  
long nStartPos; //File Snippet Start Position 9~a_^m/  
long nEndPos; //File Snippet End Position ~]N% {;F}  
int nThreadID; //Thread's ID 2PRGwK/  
boolean bDownOver = false; //Downing is over ? [ =P  
boolean bStop = false; //Stop identical ofS9h*wrJ  
FileAccessI fileAccessI = null; //File Access interface c sYICLj  
kD2MqR>  
fz<Y9h=  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _oR6^#5#  
{  =#8J9  
this.sURL = sURL; NAL%qQ  
this.nStartPos = nStart; \@5W&Be^  
this.nEndPos = nEnd; $U!w#|&  
nThreadID = id; x`a@h\ n  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d ;ry!X  
} e;Q~P]x  
Lc+)#9*d  
iTD{  
public void run() =PXNg!B}D*  
{ I_v]^>Xw  
while(nStartPos < nEndPos && !bStop) 8 #0?  
{ _QCAV+K'  
iPxSVH[  
N+h|Ffnp  
try{ 6? 2/b`k  
URL url = new URL(sURL); UGl}=hwKkG  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E|#'u^`yv  
httpConnection.setRequestProperty("User-Agent","NetFox"); wtMS<$  
String sProperty = "bytes="+nStartPos+"-"; !! #\P7P  
httpConnection.setRequestProperty("RANGE",sProperty); 8iq~ha$]|  
Utility.log(sProperty); jt?R a1Z  
nLYyS#  
=n%?oLg^  
InputStream input = httpConnection.getInputStream(); ^fH]Rlx  
//logResponseHead(httpConnection); ]kc]YO7i%R  
P%.9g  
z.#gpTXD  
byte[] b = new byte[1024]; \\)3:1X  
int nRead; 6VRVk7"  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #uKHw2N  
{ aNfgSo05@n  
nStartPos += fileAccessI.write(b,0,nRead); (n#  
//if(nThreadID == 1) eD G=-a4  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S tn[M|  
} =T;%R^@  
^k~{6S,  
>pz/wTOi  
Utility.log("Thread " + nThreadID + " is over!"); -K+grsb g  
bDownOver = true; +STT(bMn  
//nPos = fileAccessI.write (b,0,nRead); R0{+Xd  
} v^JyVf>  
catch(Exception e){e.printStackTrace ();} %J3#4gG^v  
} B7va#'ne4{  
} _k _F  
kf^Wzp  
;p1%KmK3  
//打印回应的头信息 0A\o8T.12  
public void logResponseHead(HttpURLConnection con) 2qw~hWX  
{ e(j"u;=  
for(int i=1;;i++) iQS?LksQX  
{ 6$2)m;| XY  
String header=con.getHeaderFieldKey(i); p}N'>+@=  
if(header!=null) !j [U  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3K P6M=  
Utility.log(header+" : "+con.getHeaderField(header)); Yr!<O&=  
else Z5_MSPm  
break; }Li24JK  
} ^PO0(rh  
} @^/JNtbH!  
zI(b#eUF  
DS-Kot(k(z  
public void splitterStop() <"aPoGda  
{ #>[+6y]U!  
bStop = true; v-4eN1OS  
} SbrBlP: G  
liPUK#  
^hTq~"  
} YgrBIul  
'^}l|(  
$:F]O$A  
/* *m2J$9q  
**FileAccess.java N!^U{;X7/  
*//文件访问(定位,写) Bglh}_X  
package NetFox; RwN*/Li  
import java.io.*; bQEQHqY5  
866n{lyL  
?zKDPBj  
public class FileAccessI implements Serializable{ *}cF]8c5W  
MZ6?s(mkx  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '9H]S Ew  
RandomAccessFile oSavedFile; MX6;ww  
long nPos; `fc2vaSH =  
T<?JL.8g_  
(N0G[(>  
public FileAccessI() throws IOException *}A J7]  
{ |_ E)2b:h  
this("",0); !&ac}uD^g  
} M%sWtgw(  
=M ?  
tb^3-ZUb  
public FileAccessI(String sName,long nPos) throws IOException XEY((VL0  
{ zEpcJHI%  
oSavedFile = new RandomAccessFile(sName,"rw"); 9kQ~)4#  
this.nPos = nPos;  ,`)!K}2  
oSavedFile.seek(nPos); Sh}AGNE'  
} eB^:+h#A_  
8xZN4ck_@  
Z_cTuu0'  
public synchronized int write(byte[] b,int nStart,int nLen) m?>$!B4jFB  
{ qP*$wKY,  
int n = -1; :1s6h%evrT  
try{ '72ZLdi}-  
oSavedFile.write(b,nStart,nLen); 66Huqo  
n = nLen; ?UQE;0 B  
} ~g~z"!K  
catch(IOException e) VctAQ|h^  
{ DpoRR`  
e.printStackTrace (); b:Wl B[5  
} -D`*$rp,  
TBvv(_  
4Ts5*_  
return n; 83Bp_K2\  
} ;HgV(d#X  
~;3N'o  
LezM=om.  
} ie=tM'fb  
%koHTWT+  
iK s/8n  
/* V2V^*9(wu@  
**SiteInfoBean.java XW%!#S&;X  
*/ Cj31'  
package NetFox; *3s4JK  
Y*dzoN.sW  
4-lEo{IIM  
public class SiteInfoBean { d {T3  
;sS N  
YJ_LD6PL9  
private String sSiteURL; //Site's URL "fL:scq@0  
private String sFilePath; //Saved File's Path th2a'y=0  
private String sFileName; //Saved File's Name ZH~T'Bg  
private int nSplitter; //Count of Splited Downloading File *U)!9DvA  
h7wm xa;  
v;80RjPy>  
public SiteInfoBean() /~K-0K#w  
{//nSplitter的缺省值为5 0Zs}y\J`  
//default value of nSplitter is 5 BI3Q~ADV  
this("","","",5); uF+if`?  
} )?:V5UO\  
7eqax33f  
(B}+uI{  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |l 03,dOF  
{ Q+U}    
sSiteURL= sURL; %mAgE\y25  
sFilePath = sPath; l+*^P'0u  
sFileName = sName; u0Fu_Rtr  
this.nSplitter = nSpiltter; pBG(%3PpW  
`sAz1/N  
x%jJvwb^|  
} _}vD?/$L  
FQ*4?D,A  
9P#E^;L  
public String getSSiteURL() _iO,GT=J-  
{ =P<gZ-Cm  
return sSiteURL; Wt"fn&R}  
} A<C`JN}  
:lcZ )6&S  
g PU|Gv5  
public void setSSiteURL(String value) $ o?Wum  
{ .#2YJ~  
sSiteURL = value; pE[ul  
} c6:"5};_  
8&7LF  
35%'HFt_  
public String getSFilePath() zZ3,e L  
{ I!%T!B540  
return sFilePath; Em N0K'x  
} Bmm#5X@*  
>%h_ R:  
%fGS< W;  
public void setSFilePath(String value) #joGIw  
{ " 6Hka{  
sFilePath = value; ==F[5]?  
} >?ZH[A  
h3$.` >l  
U N1HBW;  
public String getSFileName() : |#Iw  
{ q+>J'UGb  
return sFileName; AkrUb$ }  
} yQ?N*'}$  
<.s=)}'`P  
/%\E2+6  
public void setSFileName(String value) X3NHQMI   
{ {w$1_GU  
sFileName = value; 7hqa|  
} %3M(!X:[  
t,4q]Jt  
\Lv eZ_h5  
public int getNSplitter() lpQsmd#  
{ *y9 iuJ}  
return nSplitter; rR@ t5  
} 6UXa 5t  
>:!TfuU^R  
rj&  
public void setNSplitter(int nCount) qOVs9'R  
{  O;h]  
nSplitter = nCount; (9]`3^_,J  
} ,R5NKWo  
} <7fF9X  
h7c8K)ntnf  
X3vTyIsn  
/* uvz}qH@j/Q  
**Utility.java V'sp6:3*\  
*/ ,'?%z>RZm  
package NetFox; 7^P!@o$v!  
Pou-AzEP$  
>Ip>x!wi  
public class Utility { Qctm"g|  
=|O`al  
`X'-4/Y  
public Utility() !Sx }~XB<  
{ B.vg2N  
:j)H;@[I  
S^? @vj  
} jFf2( AR  
( >zXapb2  
//线程睡眠 /bv `_ >  
public static void sleep(int nSecond) *T' /5,rX2  
{ u1s^AW8 y  
try{ #m{K  
Thread.sleep(nSecond); 12n5{'H2%  
} J;,6ydf8!  
catch(Exception e) {Hm0Q  
{ u;18s-NY  
e.printStackTrace (); %wn|H>  
} C8>zr6)1  
} M/C7<?&  
Aq@_^mq1A  
//日志 0 {#c  
public static void log(String sMsg) "vQ$RW -  
{ 0|E!e  
System.err.println(sMsg); N>!RKf:ir  
} "PK\;#[W|  
NXb_hF  
0l#gS;  
public static void log(int sMsg) `W,gYH7  
{ 6AV@O  
System.err.println(sMsg);  KoVy,@  
} ]BGWJA5  
} 8mI eW  
NPc]/n?vDj  
L)H' g  
/* hn\<'|n  
**TestMethod.java j3jf:7 /\  
*/ 2V %si6  
package NetFox; ${Cb1|g>j  
`p1szZD&  
Se/VOzzg  
public class TestMethod { U\'.rT[#  
NKf][!bi  
#ak2[UOT  
public TestMethod() i lk\&J~I  
{ ///xx/weblogic60b2_win.exe 5m{!Rrb  
try{ 8##-fv]  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :%cL(',Q  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~`)`Ip  
SiteFileFetch fileFetch = new SiteFileFetch(bean); N)|mA)S)  
fileFetch.start(); L1ZhH3}X  
} yo]!Zn  
catch(Exception e){e.printStackTrace ();} %> Z;/j|#r  
E/z^~;KA  
~H!s{$.5  
} '0)a|1,  
fQ c%a1'  
MUsF/1  
public static void main(String[] args) ka? |_(  
{ vHSX3\(  
new TestMethod(); )\#w=P  
} 3`[f<XaL  
} mpfc2>6Il.  
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