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http断点续传简单实现(java)

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/* bdL= ?KS  
**SiteFileFetch.java \5a.JfF  
*/ coXg]bUKo  
package NetFox; \c2x udU  
import java.io.*; \,13mB6  
import java.net.*; O>L,G)g  
3t-STk?  
t oGiG|L  
public class SiteFileFetch extends Thread { Lf(( zk:pt  
_^W;J/He  
nF'YG+;|@  
SiteInfoBean siteInfoBean = null; //文件信息Bean _tHhS@   
long[] nStartPos; //开始位置 t#"0^$l=  
long[] nEndPos; //结束位置 x/?ET1iGt  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 l7g'z'G  
long nFileLength; //文件长度 lWYp  
boolean bFirst = true; //是否第一次取文件 o MJ `_  
boolean bStop = false; //停止标志 AJ%E.+@=r  
File tmpFile; //文件下载的临时信息 !~|-CF0z=  
DataOutputStream output; //输出到文件的输出流 a U\|ZCH\]  
@dv8 F "v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) U> lf-iI2B  
public SiteFileFetch(SiteInfoBean bean) throws IOException (T*$4KGV  
{ HaVhdv3L  
siteInfoBean = bean; bq E'9GI  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 5z_d$.CIc  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); m'N AM%$}J  
if(tmpFile.exists ()) :rL%,o"  
{ Zkd{EMW  
bFirst = false; Q7uJ9Y{X  
read_nPos(); nW)+-Wxq  
} w1G(s$;C  
else  ?CAU+/  
{ !ekByD  
nStartPos = new long[bean.getNSplitter()]; \!\:p/f  
nEndPos = new long[bean.getNSplitter()]; @S3L%lOH  
} n=-vOa%  
W%+02_/)  
bR7tmJ[)Z  
a>vxox) %  
} $?F_Qsy{d  
%J6>Vc!ix=  
KYkS ^v  
public void run() kK6t|Yn&  
{ {6LS$3}VM  
//获得文件长度 \gT({XU?  
//分割文件 UK'8cz9  
//实例FileSplitterFetch ,I|^d.[2  
//启动FileSplitterFetch线程 Jm=3 %H  
//等待子线程返回 .`KzA]&#  
try{ SIM> Lz  
if(bFirst) UH&1QV  
{ mb_6f:Qh3  
nFileLength = getFileSize(); hH$9GL{H  
if(nFileLength == -1) vytO8m%U  
{ y9T 5  
System.err.println("File Length is not known!"); 0}` -<(  
} =(R3-['QIb  
else if(nFileLength == -2) [\0>@j}Z  
{ r|z B?9Q  
System.err.println("File is not access!"); Om;` "5  
} 00>knCe6  
else EpT^r8I  
{ benqm ~{\  
for(int i=0;i<nStartPos.length;i++) 5)rN#_BKj  
{ _$8:\[J  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ra@CouR^c{  
} u{sb^cmy  
for(int i=0;i<nEndPos.length-1;i++) oykb8~u}}  
{ V1Gnr~GM  
nEndPos = nStartPos[i+1]; w xa MdA  
} fgA-+y  
nEndPos[nEndPos.length-1] = nFileLength; <1QXZfQ"  
} 7T t!h f  
} (Nv -wU  
Q{L:pce-  
O=(F46 M  
//启动子线程 >X' -J{4R  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kP ,8[r  
for(int i=0;i<nStartPos.length;i++) LROrhO  
{ Ro4!y:2|  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '=xO?2U-Z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,Q.[Lc=w  
nStartPos,nEndPos,i); rY8(`a  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rBi6AM/  
fileSplitterFetch.start(); 2##mVEo.(  
} jbUg?4k!  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0)7v _|z  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fEiNHVx  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *YGj^+   
nEndPos = " + nFileLength); B-$zioZ  
// fileSplitterFetch[nPos.length-1].start(); &9z&#`AY]>  
=iPQ\_ON@  
k${F7I(Tb  
//等待子线程结束 9, 792b  
//int count = 0; Wy$Q!R=i  
//是否结束while循环 GJuU?h#:/{  
boolean breakWhile = false; O,KlZf_B  
yAVt[+0  
oRCD8b?  
while(!bStop) gJBk&SDgtP  
{ cK+)MFOu+  
write_nPos(); 7PI|~Ifi  
Utility.sleep(500); \[x4  
breakWhile = true;  3Kum  
Jz\'%O'  
ALiXT8q  
for(int i=0;i<nStartPos.length;i++) Pz1pEyuL  
{ 0> m-J  
if(!fileSplitterFetch.bDownOver) kfBVF%90  
{ oToUpkAI  
breakWhile = false;  `' 5(4j  
break; T'l >$6  
} `Q*L!/K+  
} [= -?n6  
if(breakWhile) 4*_9Gl  
break; =LS?:Mhm  
-Vk+zEht  
]w(i,iJ  
//count++; .Kr?vD^nG  
//if(count>4) 41WnKz9c  
// siteStop(); x(7K=K']  
} <5A(rDij  
-U(T  
Zycu3%JI  
System.err.println("文件下载结束!"); HP2]b?C  
} auqM>yx  
catch(Exception e){e.printStackTrace ();} =)(o(bfSKr  
} g6k@E,cI_  
# &o3[.)9  
|Z<NM#1  
//获得文件长度 1y l2i|m+  
public long getFileSize() 6{O#!o*g  
{ ,+p&ZpH  
int nFileLength = -1; " mKMym2  
try{ E)(`Z0  
URL url = new URL(siteInfoBean.getSSiteURL()); o]NL_SM_  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^$][ah  
httpConnection.setRequestProperty("User-Agent","NetFox"); -25#Vh  
;O YwZ  
^q"wd?((h  
int responseCode=httpConnection.getResponseCode(); -t9oL3J  
if(responseCode>=400) %iPu51+=  
{ Isq3YY  
processErrorCode(responseCode); 'e6 W$?z  
return -2; //-2 represent access is error MDkIaz\U  
} ixJUq o  
;F&wGe  
0w >DU^+  
String sHeader; Q^Ln`zMe  
bG&qgbN>  
Qv=Z  
for(int i=1;;i++) :OZhEBL&b  
{ VsMNi#?  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !'MD8  
//Utility.log(in.readLine()); 1e+?O7/  
sHeader=httpConnection.getHeaderFieldKey(i); VA%i_P,  
if(sHeader!=null) Y'~&%|9+T  
{ 18HHEW{  
if(sHeader.equals("Content-Length")) !Yf0y;e|:  
{ #e=^-yE  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sg2C_]i,H  
break; j%h Y0   
} CUG<v3\  
}  M:$nL  
else 7L6M#B[)e5  
break; ZSSgc0u^?  
} D-!%L<<  
} ~e8n yB  
catch(IOException e){e.printStackTrace ();} ,m8*uCf  
catch(Exception e){e.printStackTrace ();} ~k(Ez pn#  
e- CW4x  
m t^1[  
Utility.log(nFileLength); BSf"'0I&  
Qa%SvA@R  
w1b <>A?87  
return nFileLength; SAJ=)h~  
} UXJl;M b  
n}?G!ySg  
~dLZ[6Z  
//保存下载信息(文件指针位置) '1 $({{R  
private void write_nPos() <hbbFL}|%  
{ nE;gM1I  
try{ IycxRig  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~=ktFuEa  
output.writeInt(nStartPos.length); Biy 9jIWI  
for(int i=0;i<nStartPos.length;i++) R2`g?5v  
{ A~V\r<N j  
// output.writeLong(nPos); Se8y-AL6x>  
output.writeLong(fileSplitterFetch.nStartPos); Qknc.Z}  
output.writeLong(fileSplitterFetch.nEndPos); sD +G+  
} ^nF$<#a  
output.close(); dDbC0} x/  
} Hrnql  
catch(IOException e){e.printStackTrace ();} xk8p,>/  
catch(Exception e){e.printStackTrace ();} O$/ swwB!  
} z:5ROlk0  
F4%[R)  
Dys"|,F  
//读取保存的下载信息(文件指针位置) e~;)-Z  
private void read_nPos() MlE~ gCD  
{ yZ$;O0f&&  
try{ 3+5\xRq  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J*X.0&Toc  
int nCount = input.readInt(); Xy<f_  
nStartPos = new long[nCount]; FF~4y>R7u  
nEndPos = new long[nCount]; O Zm[i H  
for(int i=0;i<nStartPos.length;i++) wR4u}gb#q  
{ #!,`EU  
nStartPos = input.readLong(); /exl9Ilt]  
nEndPos = input.readLong(); $yFuaqG`Wo  
} NV4W2thYo  
input.close(); 'a?.X _t  
} k.[) R@0%  
catch(IOException e){e.printStackTrace ();} rxp9B>~  
catch(Exception e){e.printStackTrace ();} G%jJ>T4  
} , %O3^7i  
kQlcT"R  
x>" JWD  
private void processErrorCode(int nErrorCode) A!Ct,%   
{ 6_K#,_oZ  
System.err.println("Error Code : " + nErrorCode); S_VncTIO  
} @SG"t,5s  
R bc2g"]  
.x?zky^  
//停止文件下载 "d>g)rvOc  
public void siteStop() H6S vU  
{ 4qXRDsbCf  
bStop = true; Rn_W|"  
for(int i=0;i<nStartPos.length;i++) i3&B%JiLX  
fileSplitterFetch.splitterStop(); 1\{U<Oli  
xj q7%R_,  
YGV#.  
} #33RhJu5,  
} ^*ez j1  
//负责部分文件的抓取 gIM'bA<~  
**FileSplitterFetch.java 15T[J%7f  
*/ )'dH}3Ba  
package NetFox; =/QU$[7X(  
;(0$~O$3u  
.C;_4jE  
import java.io.*; ?r E]s!K  
import java.net.*; %x8`fm  
dtnet_j  
HGQ?(2]8$  
public class FileSplitterFetch extends Thread { C"^hMsU8  
r{2].31'  
xm,`4WdG  
String sURL; //File URL ?-::{2O)  
long nStartPos; //File Snippet Start Position ,ibPSN5Ca  
long nEndPos; //File Snippet End Position d J%Rk#?;A  
int nThreadID; //Thread's ID b'oGt,  
boolean bDownOver = false; //Downing is over 1H,tP|s  
boolean bStop = false; //Stop identical X*9N[#wu6  
FileAccessI fileAccessI = null; //File Access interface $n#Bi.A j  
T<e7(=  
1.95 ^8  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YaNH.$.:  
{ ;y~{+{{Ow  
this.sURL = sURL; y-\A@jJC5  
this.nStartPos = nStart; g?[& 0r1  
this.nEndPos = nEnd; {pb9UUP2  
nThreadID = id; ^2C /!Y<  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4o4 =  
} MYhx'[4[3  
7.e7Fi{  
%t`SSW7I  
public void run() pPyvR;NJ  
{ mYh5#E41J  
while(nStartPos < nEndPos && !bStop) oO#xx)b  
{ I& M36f  
&`yOIX-H_  
^6a S]t  
try{ 2\nN4WL 5.  
URL url = new URL(sURL); IObx^N_K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1O7]3&L@  
httpConnection.setRequestProperty("User-Agent","NetFox"); ;;?vgrz  
String sProperty = "bytes="+nStartPos+"-"; .B'UQ|NR  
httpConnection.setRequestProperty("RANGE",sProperty); ',JrY)  
Utility.log(sProperty); ,'C30A*p  
1^L`)Up  
(rr}Pv%yb  
InputStream input = httpConnection.getInputStream(); j1puB  
//logResponseHead(httpConnection); Zn@W7c,_I  
h@~:(:zU$  
JAlU%n?R  
byte[] b = new byte[1024]; w{3Q( =&  
int nRead; W}XYmF*_?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tx0Go'{  
{ ~^I\crx,U%  
nStartPos += fileAccessI.write(b,0,nRead); i s L{9^  
//if(nThreadID == 1) {)V?R  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k7^R,.c@  
} M%$ DT  
JF M"ii{8  
a-]hW=[  
Utility.log("Thread " + nThreadID + " is over!"); N%9h~G  
bDownOver = true; e,f ;  
//nPos = fileAccessI.write (b,0,nRead); t`"^7YFS>  
} 9W*.lf  
catch(Exception e){e.printStackTrace ();} fyI_  
} b'velj3A  
} ajn-KG!A  
F =XF]  
Fr-[UZ~V  
//打印回应的头信息 M h`CP  
public void logResponseHead(HttpURLConnection con) '#v71,  
{ #gh p/YoTq  
for(int i=1;;i++) _6;<ow  
{ ZjqA30!  
String header=con.getHeaderFieldKey(i); Kw)K A^KF  
if(header!=null) cV-i*L4X  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OI+E (nA  
Utility.log(header+" : "+con.getHeaderField(header)); 3&es]1b  
else Qi_&aU$>lM  
break; tNU-2r   
} 4=xq:Tf  
} FQROK4x%"  
]9*;;4M g  
@DuK#W"E u  
public void splitterStop() zmiZ]uq  
{ A2NF<ZsD  
bStop = true; g6%Z)5D]!  
} h%TLD[[/jr  
%v{1# ~u  
ZYcd.?:6  
} PK 4`5uT  
xx }GOY.J  
M4KWN'  
/* SdJ/ 4&{ !  
**FileAccess.java 'e@=^FC  
*//文件访问(定位,写) x6;j<m5Mjx  
package NetFox; Dx-KMiQ,"(  
import java.io.*; 5f^>b\8+ |  
gsPl _  
DG[%Nhle  
public class FileAccessI implements Serializable{ PB9/m-\H  
hO#t:WxFI  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [ohBPQO  
RandomAccessFile oSavedFile; A&,,9G<  
long nPos; R^n@.^8s  
F[Q!d6  
a{'Z5ail  
public FileAccessI() throws IOException yz\c5  
{ * R d#{Io7  
this("",0); xHo&[{  
} SDYv(^ f ,  
uD9|.P}  
F|+W.9  
public FileAccessI(String sName,long nPos) throws IOException "D][e'  
{ ^2JpWY:|7  
oSavedFile = new RandomAccessFile(sName,"rw"); :I1_X  
this.nPos = nPos; MYLsHIPC  
oSavedFile.seek(nPos); l=}~v  
} JkQ\)^5v  
'5KeL3J;  
89~ =eY  
public synchronized int write(byte[] b,int nStart,int nLen) &miexSNeF  
{ en*d/>OVJ  
int n = -1; 0N:XIGFa  
try{ !CUoHTmB  
oSavedFile.write(b,nStart,nLen); nV_8Ke  
n = nLen; E=]4ctK  
} <Fz~7WVd  
catch(IOException e) od' /%  
{ [ ho (z30k  
e.printStackTrace (); .dMVoG5  
} t.Nb? /  
%?Y[Bk3p  
_<c$)1  
return n; #/2$+x  
} [K/m  
0\9K3  
Px FWJ?=  
} N_pUv   
p>vU?eF  
IuF_M<d,  
/* cvd\/pG)  
**SiteInfoBean.java 4QOEw-~w&s  
*/ [BBEEI=|r  
package NetFox; u+H ; @  
X1{[}!  
e=vsuqGT  
public class SiteInfoBean { ew _-Eb  
zq+o+o>xo  
Ian[LbCWB  
private String sSiteURL; //Site's URL 66x?A0P  
private String sFilePath; //Saved File's Path ".^VI2T  
private String sFileName; //Saved File's Name m %;D  
private int nSplitter; //Count of Splited Downloading File &8.NT~"Gg  
5tjP6Z`!9`  
8to8!(  
public SiteInfoBean() uiq^|5Z  
{//nSplitter的缺省值为5 i) E|bW;  
//default value of nSplitter is 5 /sM~U q?  
this("","","",5); fXI:Y8T  
} n Ox4<Wk&  
=K'cM=WM6  
zO g7raIa  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ()&~@1U  
{ CLvX!O(~  
sSiteURL= sURL; r.7$&BCng  
sFilePath = sPath; ODZ|bN0>  
sFileName = sName; Q.K,%(^;a  
this.nSplitter = nSpiltter; #\=FO>  
!r<pmr3f@7  
@;"|@!l|  
} V:joFRH9  
Zu7)gf  
ui?  
public String getSSiteURL() LGn:c;  
{ 'dn]rV0(C  
return sSiteURL; 2'w?\{}D  
} 1jcouD5?H  
E 7{U |\  
~A\GT$  
public void setSSiteURL(String value) F%RRd/'  
{ yK=cZw%D  
sSiteURL = value; 5?x>9C a  
} x<ZJb  
XuFYYx~ ^3  
p^w;kN  
public String getSFilePath() JJN.ugT}1  
{ vQ 6^xvk]  
return sFilePath; n"c[,k+R`U  
} ?Wlb3;  
{ttysQ-  
MDnua  
public void setSFilePath(String value) (,0(   
{ 8<QdMkI  
sFilePath = value;  "y}--  
} !$gR{XH$]  
AP 2_MV4W  
8}O lL,fP  
public String getSFileName() p8Qk 'F=h  
{ vdc\R?  
return sFileName; rlOAo`hd  
} ia!y!_L\'  
OrY/`+Cog  
r@H /kD  
public void setSFileName(String value) nFHUy9q  
{ @@Kp67Iv  
sFileName = value; EE06h-ns  
} 2} /aFR  
NJWA3zz   
.ypL=~Rp  
public int getNSplitter() Ot_]3:`J~  
{ wd8 l$*F*  
return nSplitter; B" 1c  
} rr],DGg+B]  
6H.0vN&  
PUMXOTu]  
public void setNSplitter(int nCount) H)kwQRfu  
{ |6sp/38#p  
nSplitter = nCount; 823Y\x~>  
} U)] oO  
} ?jv/TBZX4  
N2^=E1|_  
 MzdV2.  
/* NRs13M<ftf  
**Utility.java JE "x  
*/ AUG#_HE]k  
package NetFox; 6jD=F ^jw  
oGnSPI5KGC  
4 #MtF'J  
public class Utility { y@S$^jk.  
k_#ak%m/  
{#vgtgBB  
public Utility() gV's=cQ  
{  ~d.Y&b  
XJ;57n-?  
J/y83@  
} hR?{3d#x2  
hn G Z=  
//线程睡眠 cA?W7D  
public static void sleep(int nSecond) I5 p ? [  
{ Qz1E 2yJ  
try{ UcHJR"M~c  
Thread.sleep(nSecond); W' VslZG  
} Naf0)3q>!  
catch(Exception e) ~Fcm[eoC  
{ k(nW#*N_  
e.printStackTrace (); l_d5oAh   
} $ bR~+C  
} pz}.9 yI8  
-`h)$&,  
//日志 &DX! f  
public static void log(String sMsg) <)H9V-5aZ  
{ .uZ3odMlx  
System.err.println(sMsg); +mj y<~\  
} *w\W/Y  
B~ GbF*j  
.|70;  
public static void log(int sMsg) i[3'ec3  
{ aB&&YlR=n<  
System.err.println(sMsg); UB@+c k  
} +I|vzz`ZVr  
} 7Ovi{xd@  
\r+ a GB  
ea 'D td  
/* }&J q}j  
**TestMethod.java 'zTLl8P  
*/ 1>h]{%I  
package NetFox; <\^8fn   
VY4yS*y  
c-5)QF) z  
public class TestMethod {  ZBp/sm  
H<,gU`&R  
\_f(M|  
public TestMethod() +ye3HGD  
{ ///xx/weblogic60b2_win.exe n/:33DAB  
try{ @*( (1(q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8<Av@9 *}  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oUU1+F-  
SiteFileFetch fileFetch = new SiteFileFetch(bean); E:nF$#<'N  
fileFetch.start(); zQd 2  
} k5pN  
catch(Exception e){e.printStackTrace ();} [7Oe3=  
N`e[:[  
zK@@p+n_#.  
} (*iHf"=\  
U>N1Od4vTO  
2BwO!Y[  
public static void main(String[] args) ,k3FRes3  
{ }qD\0+`qi  
new TestMethod(); gg2( 5FPP  
} 4o[{>gW  
} pEA:L$&  
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