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http断点续传简单实现(java)

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/* o]vdxkU]  
**SiteFileFetch.java b(yY.L=K  
*/ ]T$~a8  
package NetFox; l}m@9 ~oC  
import java.io.*; #>0nNR[$Y  
import java.net.*; }\@*A1*X2  
mVxS[Gq  
)9*WmFc+#  
public class SiteFileFetch extends Thread { *]LM2J  
5b&'gd^d  
30<^0J.1  
SiteInfoBean siteInfoBean = null; //文件信息Bean bV"0}|A~K  
long[] nStartPos; //开始位置 YRK4l\_`  
long[] nEndPos; //结束位置 =hA/;  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 /q=<OEC  
long nFileLength; //文件长度 ^71sIf;+  
boolean bFirst = true; //是否第一次取文件 qU"+0t4  
boolean bStop = false; //停止标志 $V[ob   
File tmpFile; //文件下载的临时信息 76 y}1aa  
DataOutputStream output; //输出到文件的输出流 UZyo:*yB  
*aSFJK  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) $ZA71TzMV  
public SiteFileFetch(SiteInfoBean bean) throws IOException `18G 5R  
{ /h_BF\VBs  
siteInfoBean = bean; n@*NQ`(_  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); [P^ .=F  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); WPPmh~:  
if(tmpFile.exists ()) 6s6[sUf=l&  
{ qLR)>$  
bFirst = false; Agl[Z>Q  
read_nPos(); zEu*q7  
} =KX:&GU  
else NK#f Gz*,(  
{ C&Rv)j  
nStartPos = new long[bean.getNSplitter()]; qp7>_B  
nEndPos = new long[bean.getNSplitter()]; G,J$lT X  
} @Fo0uy\ G  
o/Z?/alt4  
y'(;!5w  
K\uR=L7  
} 6%)dsTAB  
!4|7U\;  
HH>]"mv  
public void run() "]sr4Jg=  
{ zgLm~  
//获得文件长度 .7oz  
//分割文件 [ z?<'Tj  
//实例FileSplitterFetch o0AREZ+I  
//启动FileSplitterFetch线程 f;QWlh"9  
//等待子线程返回 NbSwn}e_  
try{ f@Db._ E  
if(bFirst) 'E6)6N  
{ myH#.$=A  
nFileLength = getFileSize(); !.9NJ2'8  
if(nFileLength == -1) L='GsjF0}  
{ 0%v p'v  
System.err.println("File Length is not known!"); &7;W=uF  
} q K]Wk+  
else if(nFileLength == -2) =E{1QA0  
{ QH+Oi&xH  
System.err.println("File is not access!"); Z(Xu>ap  
} 5=l Ava#  
else Zd042 %  
{ MwiT1sB~  
for(int i=0;i<nStartPos.length;i++)  75%!R  
{ gg933TLu(Q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); @dGj4h.  
} =*}|y;I  
for(int i=0;i<nEndPos.length-1;i++) R`Q9|yF\  
{ JPmW0wM  
nEndPos = nStartPos[i+1]; h T4fKc7P  
} [gU z9iU  
nEndPos[nEndPos.length-1] = nFileLength; EyozhIV  
} x#U?~6.6  
} WG9x_X&XJ  
zDC-PHF HQ  
41$7P[M;  
//启动子线程 [9X1;bO#f  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <wa}A!fu  
for(int i=0;i<nStartPos.length;i++) iB{O"l@w  
{ LvB-%@n  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), /,wG$b+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >wZ!1Jq  
nStartPos,nEndPos,i); CJ?Lv2Td  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ._#|h5  
fileSplitterFetch.start(); p^NYJV  
} UDhW Y.`'~  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #VtlXr>G  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?NJ\l5'  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &vo]l~.  
nEndPos = " + nFileLength);  R:-^,/1  
// fileSplitterFetch[nPos.length-1].start(); 0Bb amU  
N_h)L`  
H+t^eg88  
//等待子线程结束 "|(+~8[  
//int count = 0; BoXQBcG]w  
//是否结束while循环 ur"cku G!9  
boolean breakWhile = false; 5yuR[ VU  
njX!Ez  
6*Rz}RQ  
while(!bStop) LC2t,!RRl&  
{ ]hc.cj`\W&  
write_nPos(); [ q22?kT  
Utility.sleep(500); y1B3F5  
breakWhile = true; 8nW#Q <s  
1Sr@$+VGO  
LsoP >vJG  
for(int i=0;i<nStartPos.length;i++) uee2WGD  
{ \f05(ld  
if(!fileSplitterFetch.bDownOver) &K/5AH"q  
{ kF`2%g+  
breakWhile = false; gCW.;|2  
break; :voQ#f=  
} Syo1Dq6z.  
} bR(rZu5  
if(breakWhile) H4MFTnJ{  
break; d?.ewsC  
{a\m0Bw/  
"xi)GH]H_  
//count++; KYZ/b8C  
//if(count>4) ]W]o6uo7  
// siteStop(); NN>,dd3T  
} =;4cDmZh  
\IQf|  
A7C+-N  
System.err.println("文件下载结束!"); T32C=7  
} $b QD{ {  
catch(Exception e){e.printStackTrace ();} N[~ RWg  
} iG!tRNQ{y  
Dqs{ n?@n  
c R*D)'/tl  
//获得文件长度 ~K5eO-  
public long getFileSize() X3 P~z8_  
{ 4 bw8^  
int nFileLength = -1; E.R,'Y;x  
try{ Ivmiz{Oii  
URL url = new URL(siteInfoBean.getSSiteURL()); lQ {k  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .i) H1sD  
httpConnection.setRequestProperty("User-Agent","NetFox"); <j+DY@*  
bx#GOK-  
/PafIq  
int responseCode=httpConnection.getResponseCode(); ZBUEg7c  
if(responseCode>=400) n<+g{QHi  
{ |Ah'KpL8W  
processErrorCode(responseCode); w^6rgCl  
return -2; //-2 represent access is error `A_CLVE  
} KmG*`Es  
W1dpKv  
8M <q-sn4B  
String sHeader; d="Oge8  
@GNNi?EY  
i7 _Nv  
for(int i=1;;i++) 1RgtZp%  
{ D2z" Z@  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7o_1PwKS6  
//Utility.log(in.readLine()); j^-E,YMC  
sHeader=httpConnection.getHeaderFieldKey(i); mnh>gl!l  
if(sHeader!=null) ;x^WPY Ej  
{ .jA'BF.  
if(sHeader.equals("Content-Length")) P:,'   
{  >\6Tm  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); bFD vCF  
break; K%h9'}pq>1  
} ux`)jOQ`Y]  
} <&^P1x<x  
else 6O"?wN%$  
break; |Ii[WfFA|J  
} .0+=#G>  
} :Aj8u\3!@  
catch(IOException e){e.printStackTrace ();} GrPKJ~{6  
catch(Exception e){e.printStackTrace ();}  ieo Naq  
lQ(I/[qVd  
-5B>2K F  
Utility.log(nFileLength); X67^@~l  
Aj#bhv  
tUU`R{=(  
return nFileLength; 8S/SXyS  
} *'[8FZ|dQ  
@-ps[b`z  
?&A)%6` ~  
//保存下载信息(文件指针位置) w*#B_6bG  
private void write_nPos() }x!=F<Q!r  
{ ]z3!hgTj  
try{ >n3w'b  
output = new DataOutputStream(new FileOutputStream(tmpFile)); uy'm2  
output.writeInt(nStartPos.length); qw?#~"Ca.  
for(int i=0;i<nStartPos.length;i++) u-qwG/$E  
{ :x88  
// output.writeLong(nPos); $]LhE:!G  
output.writeLong(fileSplitterFetch.nStartPos); OD{()E?1B  
output.writeLong(fileSplitterFetch.nEndPos); ~C M%WvS  
} w(Jf;[o  
output.close(); pV:;!+  
} X?'ShXI  
catch(IOException e){e.printStackTrace ();} "}ibH{$lM  
catch(Exception e){e.printStackTrace ();} B}S!l>.z  
} K!~j}z*  
}\ kLh(  
r:N =?X`N  
//读取保存的下载信息(文件指针位置) LL% Aw)Q`  
private void read_nPos() 1'Sr0 oEd3  
{ C.]\4e  
try{ 4gD;XNrV  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); :DWvH,{+&  
int nCount = input.readInt(); WX~: Y,l+u  
nStartPos = new long[nCount]; ]]Bq te  
nEndPos = new long[nCount]; l$_q#Kd  
for(int i=0;i<nStartPos.length;i++) OeMI  
{ vX?MB  
nStartPos = input.readLong(); Lsu_ f'p0  
nEndPos = input.readLong(); >%6a$r~@  
} ]cQYSN7!SY  
input.close(); ({&\~"  
} Y6W#u iqk  
catch(IOException e){e.printStackTrace ();} U)v){g3w)  
catch(Exception e){e.printStackTrace ();} ?`T0zpC  
} |)5xmN]  
IkWV|E  
oyw*Z_9~  
private void processErrorCode(int nErrorCode) a%nksuP3  
{ n1XJ uc~  
System.err.println("Error Code : " + nErrorCode); mH`K~8pRg  
} = 1ltX+   
9!XXuMWU<  
/FJ.W<hw  
//停止文件下载 :<}1as! eo  
public void siteStop() "kb[}r4?  
{  {^8->V  
bStop = true; WR|n>i@m  
for(int i=0;i<nStartPos.length;i++) bv:M zYS  
fileSplitterFetch.splitterStop(); s8:-*VR9  
P55QE+B  
+4 W6{`  
} +jD*Jtb<  
} W _b!FQ]  
//负责部分文件的抓取 jK(]e iR$S  
**FileSplitterFetch.java reP)&Fo  
*/ VsU*yG a  
package NetFox; bT>1S2s  
2|a5xTzH  
!#[B#DZc(  
import java.io.*; rd_!'pG  
import java.net.*; ]nIH0k3y  
;9&#Sb/  
6Mc&gnN  
public class FileSplitterFetch extends Thread { Ot<vn34mt:  
r+RFDg/  
KT3n -Y-,  
String sURL; //File URL *DDqa?gQb  
long nStartPos; //File Snippet Start Position b}APD))*H!  
long nEndPos; //File Snippet End Position (J6>]MZ#)  
int nThreadID; //Thread's ID /}\Uw  
boolean bDownOver = false; //Downing is over QJ4=*tX)  
boolean bStop = false; //Stop identical ztEM>xsk  
FileAccessI fileAccessI = null; //File Access interface _8 C:Md`  
N\{{:<Cp\  
<sncW>?!~  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?y/LMja  
{ $eu-8E'  
this.sURL = sURL; ,@Fde=Lw  
this.nStartPos = nStart;  j1~'[  
this.nEndPos = nEnd; 0rrNVaM  
nThreadID = id; 1 !8 b9  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 t,]E5,1  
} xg.o7-^M  
eAl;:0=%L  
xJ rKH  
public void run() Spm0DqqR?  
{ }!_ofe  
while(nStartPos < nEndPos && !bStop) 7Zw.mM!i  
{ 2kfX_RK  
bXNM.K  
#S|DoeFs  
try{ 6%A_PP3Z  
URL url = new URL(sURL); X,mqQ7+  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i-FsA  
httpConnection.setRequestProperty("User-Agent","NetFox"); b#[EkI 0@  
String sProperty = "bytes="+nStartPos+"-"; SJ8CBxA  
httpConnection.setRequestProperty("RANGE",sProperty); B:]%Iu|  
Utility.log(sProperty); PZ.q  
&:?2IAe  
A(@VjXl  
InputStream input = httpConnection.getInputStream(); 5Tg[-tl  
//logResponseHead(httpConnection); ozOvpi:k3%  
O<>cuW(l  
elDt!9Pu  
byte[] b = new byte[1024]; _&R lR  
int nRead; @%b&(x^UD  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TbQ5  
{ N <e72x  
nStartPos += fileAccessI.write(b,0,nRead); |*5HNP  
//if(nThreadID == 1) ZnNl3MKV  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1m4Xl%KS>  
} yt[vd8O'c  
e. '6q ($3  
*Sw1b7l  
Utility.log("Thread " + nThreadID + " is over!"); jU2 vnGw_  
bDownOver = true; MO-7y p:K  
//nPos = fileAccessI.write (b,0,nRead); o>jM4sk$  
} Ad)::9K?J  
catch(Exception e){e.printStackTrace ();} 6 k+4R<  
} WlHK  
} X:kr$  
> }fw7X  
Bm$(4  
//打印回应的头信息 _^MkC} 8  
public void logResponseHead(HttpURLConnection con) * LOUf7`  
{ 1+ib(MJ<:#  
for(int i=1;;i++) hM "6-60  
{ AI,Jy%62/  
String header=con.getHeaderFieldKey(i); U-ADdO h"q  
if(header!=null) zI{~;`tzN  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); vE{L`,\ q  
Utility.log(header+" : "+con.getHeaderField(header)); PC)aVr?@@  
else c`O(||UZT  
break; (T|q]29  
} Ba#wW E  
} chakp!S=  
Vk:] aveW  
.8dlf7* ,  
public void splitterStop() "pMx(  
{ kCHYLv3.  
bStop = true; tl"?AQcBR  
} yOswqhz  
yFY:D2  
l|j}Ggen  
} yp?a7t M  
%DhM}f  
srQ]TYH ,  
/* C8W4~~1S  
**FileAccess.java 9D[Jn}E:  
*//文件访问(定位,写) /8Ru O  
package NetFox; 0BrAgv"3a_  
import java.io.*; HY2*5 #T  
7'zXf)!  
><wYk)0E  
public class FileAccessI implements Serializable{ O6"S=o&  
6%a:^f]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 @8eQ|.q]Q  
RandomAccessFile oSavedFile; *?3c2Jg=E  
long nPos; Ku`u%5<  
$(fhO   
.K`EflN  
public FileAccessI() throws IOException ;ZoEqMv  
{ wfQ^3HL  
this("",0); b Od<x >@  
} FH)_L1n  
>K n7A  
5 >\~jf  
public FileAccessI(String sName,long nPos) throws IOException )>;V72  
{ 952l1c!  
oSavedFile = new RandomAccessFile(sName,"rw"); *;:dJXR  
this.nPos = nPos; oM(8'{S=  
oSavedFile.seek(nPos); }l7@:ezZZ7  
} :^rt8>~  
N~|Z@pU"  
X" Upml  
public synchronized int write(byte[] b,int nStart,int nLen) mlix^P  
{ c^1tXu|&  
int n = -1; $*+IsP!  
try{ sc&u NfJ  
oSavedFile.write(b,nStart,nLen); X'J!.Jj  
n = nLen; Xv<K>i>k  
} ({0:1*lF@  
catch(IOException e) *CCh\+S7m  
{ VT [TE  
e.printStackTrace (); -?p4"[  
} {Jc.49  
:Z&<5  
^v5<*uf%m  
return n; <Uc?#;% Y}  
} fM`.v+  
)F_nK f"a  
-pW*6??+?  
} Q<>b3X>O  
5tl( $j  
Q 6n!u;  
/* 3IG<Ot9  
**SiteInfoBean.java "A]#KTP  
*/ -*$ s ;G#  
package NetFox; Zo< j"FG  
mtmTlGp6Lc  
eX'U d%  
public class SiteInfoBean { ]$i@^3`[w  
^Lv )){t  
apgR[=Oy  
private String sSiteURL; //Site's URL [`kk<$=,&  
private String sFilePath; //Saved File's Path w+u1"  
private String sFileName; //Saved File's Name NwyNl  
private int nSplitter; //Count of Splited Downloading File L;-V Yo#  
an2Yluc;  
<q&4Y+b  
public SiteInfoBean() 8d7 NESYl  
{//nSplitter的缺省值为5 ^[6el_mj  
//default value of nSplitter is 5 ..7 "<"uH  
this("","","",5); ^^B~v<uK  
} ly#jl5wmT  
I-^C6~  
yoH,4,!G  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) MML=J~1  
{ %-woaj   
sSiteURL= sURL; Wv||9[Rd  
sFilePath = sPath;  &2bqL!k  
sFileName = sName; "7Z-ACyF5  
this.nSplitter = nSpiltter; *x:*Q \|  
mKsJ[)#.  
~REfr}0  
} [ 2PPa9F  
;0lY_ii  
_2TL>1KZt  
public String getSSiteURL() 24u_}ZQzY  
{ _#qfe  
return sSiteURL; sC A  
} =Z ql6D  
E=Vp%08(  
L1Jn@  
public void setSSiteURL(String value) )|/%]@` N  
{ g`C\pdX"B  
sSiteURL = value; <eZ*LK?  
} [HI$[ :[  
U!(es0rX  
~dk97Z8  
public String getSFilePath() qw 03]a  
{ ~F8xXW0  
return sFilePath; pxn@rN#*  
} Y,Lx6kU  
5>lIrBf  
&->ngzg  
public void setSFilePath(String value) '&nQ~=3  
{ M@o^V(j  
sFilePath = value; Cu!]-c{  
} JT&RaFX  
>}:  
1m5*MY  
public String getSFileName() 3W%j^nM  
{ s (K SN/  
return sFileName; bz}-[W+  
} .TCDv4?  
pD('6C;  
5M/~ |"xk  
public void setSFileName(String value) dI|D c  
{ jweX"G54R  
sFileName = value; rsq?4+\  
} }|%1LL^pB  
hI 9q);g  
<PiO %w{  
public int getNSplitter() &isKU 8n  
{ AvPPsN0  
return nSplitter; OJd/#KFm  
} [N12X7O3  
d&\3}uH  
Z&79: 9=#>  
public void setNSplitter(int nCount) G:3szz  
{ p{}4#+-<#H  
nSplitter = nCount; A$]s{`  
} k?$I4&|5Nt  
} Cv}^]_`Q  
NWP!V@WG  
}=}wLm#&1  
/* |-;VnC&UY  
**Utility.java <uxLG;R  
*/ On54!m  
package NetFox; 2v2XU\u{t  
tt#dO@G#Fe  
6oKdw|(Q#  
public class Utility { 'u E;8.,  
.T)wG;+  
TkJ[N4'0  
public Utility() #f< v%  
{ tbWf m5$  
{VKFw=$8  
]Axz}:  
} EY:IwDA.}  
:m(DRD  
//线程睡眠 '_^T]fr}  
public static void sleep(int nSecond) z:@:B:E  
{ r fzNw  
try{ Zazff@O *  
Thread.sleep(nSecond); ^5.XQ 0n  
} dI&Q5M8  
catch(Exception e) TL)*onA9  
{ _CfJKp)  
e.printStackTrace (); g `%in  
} cPD_=.&  
} &w#!   
j:xC \b47"  
//日志  ?C#E_  
public static void log(String sMsg) ~MBPN 4r  
{ \+l*ZNYM3  
System.err.println(sMsg); Yj#tF}nPC  
} NcP/W>lN  
jj1\oyQ8  
'3Lu_]I-  
public static void log(int sMsg) OQ7 `n<I<)  
{ .w;kB}$YC  
System.err.println(sMsg); -^546 7  
} u8]FJQ*\6+  
} h693TS_N  
<^'{=A>  
#{vC =m73  
/* %IX)+ Lp`  
**TestMethod.java jx]P:]  
*/ W*t] d  
package NetFox; BMy3tyO  
@phVfP"M  
\ l#eW x  
public class TestMethod { 5&V=$]t  
])o{!}QUl\  
% /"n(?$ W  
public TestMethod() aL( hWE  
{ ///xx/weblogic60b2_win.exe 1[^YK6a/  
try{ #3QPcoxa  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b7Jxv7$e  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); iN[x *A|h  
SiteFileFetch fileFetch = new SiteFileFetch(bean); oojl"j4  
fileFetch.start(); z@i4  
} $[A\i<#  
catch(Exception e){e.printStackTrace ();} pYx,*kG:HW  
D]]wJQU2  
viG,z4Zf  
} )63 $,y-;$  
=c'4rJ$+  
kIVQ2hmv  
public static void main(String[] args) {d'-1z"q  
{ pA ~} _  
new TestMethod(); >%k6k1CZ  
}  k~ ^4  
} MQQm3VaKS  
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