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http断点续传简单实现(java)

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/* aReJ@  
**SiteFileFetch.java TMY. z  
*/ 95~bM;T Vr  
package NetFox; SO *oBA'  
import java.io.*; =TNFAt  
import java.net.*; tmq?h%O>  
}:c~5whN  
4V4S5V  
public class SiteFileFetch extends Thread { B-w`mcqp$  
u9KT_` )  
G^nG^HTo5  
SiteInfoBean siteInfoBean = null; //文件信息Bean ^gx~{9`RR  
long[] nStartPos; //开始位置 ,LxZbo!  
long[] nEndPos; //结束位置 9uWg4U  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 n/(}|xYU  
long nFileLength; //文件长度 ]58~b%s  
boolean bFirst = true; //是否第一次取文件 Cy uRj[;B  
boolean bStop = false; //停止标志 aY? VP?BL  
File tmpFile; //文件下载的临时信息 D!Y@Og.  
DataOutputStream output; //输出到文件的输出流 ?M&@# lbG  
c8[kL$b;j  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) }=R0AKz!Cv  
public SiteFileFetch(SiteInfoBean bean) throws IOException :{)uD ;  
{ 5PZ7-WJ/  
siteInfoBean = bean; Q &{C%j~N  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -r<8mL:yW  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $Ugc:L<h+  
if(tmpFile.exists ()) #~/9cVm$  
{ (nq""kO6'  
bFirst = false; .6$=]hdAp  
read_nPos(); X)hpbHa  
} 1ow,'FztPt  
else tjRw bnT"  
{ 4[x` \  
nStartPos = new long[bean.getNSplitter()]; \ [OB.  
nEndPos = new long[bean.getNSplitter()]; 8%u|[Si;  
} $`7Fk%#+e  
6M7GPHah  
0n6eWwY  
R[l`# I  
} v5\ALWy+p  
GB}\7a  
\^9n&MonM  
public void run() } %?or_f/  
{ 1)h<)  
//获得文件长度 K JOb1MM  
//分割文件 #tHYCSr]  
//实例FileSplitterFetch @]#[TbNo  
//启动FileSplitterFetch线程 0aY\(@  
//等待子线程返回 cq?,v?m  
try{ IFew3!{\  
if(bFirst) qF$y p>|#  
{ U4-RI]Cpf  
nFileLength = getFileSize(); $$.q6  
if(nFileLength == -1) v&;JVai  
{ 5lD`qY  
System.err.println("File Length is not known!"); F%$q]J[  
} K<::M3eQ  
else if(nFileLength == -2) dF 6od  
{ j*|0#q;e6  
System.err.println("File is not access!"); Mx6 yk,  
} ca3zY|Oo  
else BaI-ve  
{ 3GKKC9C6  
for(int i=0;i<nStartPos.length;i++) k3t]lG p  
{ K]B`&ih  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); |pBFmm*  
} :TP4f ?FA  
for(int i=0;i<nEndPos.length-1;i++) R'tvF$3=i  
{ A9@coP5  
nEndPos = nStartPos[i+1]; !:5'MI@  
} w@R"g%k-  
nEndPos[nEndPos.length-1] = nFileLength; zfI{cMn'J  
} HU/4K7e`  
} bXOM=T  
eP:\\; ;  
q1L>nvE  
//启动子线程 X6Z/xb@  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; q {   
for(int i=0;i<nStartPos.length;i++) ewn\'RLZ"@  
{ W f8@ B#^{  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BjPU@rS .U  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), jf1GYwuW*  
nStartPos,nEndPos,i); PE6,9i0ee  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /^jl||'H,:  
fileSplitterFetch.start(); =&k[qqxg  
} 9pj6`5Zn@6  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u@:[ dbJ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h {Jio>  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $Lbamg->E  
nEndPos = " + nFileLength); zmD7]?|  
// fileSplitterFetch[nPos.length-1].start(); OY81|N j  
6 F39'  
#+_=(J  
//等待子线程结束 iuXXFuh  
//int count = 0; }BT0dKx  
//是否结束while循环 /CyFe<t  
boolean breakWhile = false; f$5pp=s:n  
o/a2n<4  
R#y"SxD()  
while(!bStop) Dpu?JF]  
{ 98 NFJ  
write_nPos(); vpT\ CjXHZ  
Utility.sleep(500); m*B4a9 f  
breakWhile = true; )f^^hEIS  
#b)`as?!1  
|N6.:K[`  
for(int i=0;i<nStartPos.length;i++) K% snE7X?)  
{ \Ezcr=0z{j  
if(!fileSplitterFetch.bDownOver) 3rHn?  
{ ' e!WZvr  
breakWhile = false; hg<[@Q%$o  
break; BUsxgs"),  
} iyR"O1]  
} {0+WVZ4u  
if(breakWhile) pQc-}o"  
break; fyT|xI`iD  
JJg;X :p  
-@]b7J?`k  
//count++; 6!itr"  
//if(count>4) ]LxE#R5V  
// siteStop(); Ja&S_'P[  
} &M3KJ I0L  
GB}=  
dP_bFUzg  
System.err.println("文件下载结束!"); sz/^Ie-~  
} W?wt$'  
catch(Exception e){e.printStackTrace ();} 8_Uh h5[  
} :t "_I  
9(!AKKrr;  
^[bFGKE  
//获得文件长度 -O1$jBQ S  
public long getFileSize() ]n"RPktx  
{ [742s]j  
int nFileLength = -1; Nr*X1lJ6  
try{ 0!0o[3*  
URL url = new URL(siteInfoBean.getSSiteURL()); 2v@B7r4}  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); umnQ$y 0  
httpConnection.setRequestProperty("User-Agent","NetFox"); =w`uZ;l$Q  
w 2U302TZ  
Gl|n}wo$  
int responseCode=httpConnection.getResponseCode(); B6Ajcfy  
if(responseCode>=400) #l- 0$  
{ q o^mp  
processErrorCode(responseCode); ~UeTV?)  
return -2; //-2 represent access is error a%kvC#B  
} h*1T3U$  
Np$&8v+en  
o-l-Z|)7  
String sHeader; D{y7[#$h$  
H=~7g3  
*[b>]GXd49  
for(int i=1;;i++) 88S:E7 $  
{ Y}2Sr-@u  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P{QHG 3  
//Utility.log(in.readLine()); Z1 ($9hE>  
sHeader=httpConnection.getHeaderFieldKey(i); yw7(!1j=  
if(sHeader!=null) 7hPwa3D^  
{ / bH2Z  
if(sHeader.equals("Content-Length")) aMHC+R1X  
{ %-K5sIz  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 84e8z{  
break; -z-yk~F  
} Os9 EMU$  
} C'gv#!Q  
else f9kd&#O&  
break; uHmvHA~/c8  
} , #GB  
} "zXrfn  
catch(IOException e){e.printStackTrace ();} rMjb,2*rC7  
catch(Exception e){e.printStackTrace ();} 2&]LZ:(  
)Qe]!$tqfD  
I 2OQ  
Utility.log(nFileLength); `T1bY9O.  
=6=:OId  
=v<A&4  
return nFileLength; 0QfDgDX  
} -Hw3rv3o  
+ %K~  
vV 9vB3K5?  
//保存下载信息(文件指针位置) _&s pMf  
private void write_nPos() 8 qw{e`c  
{ &?1^/]'"r  
try{ olxxs(  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ln8NcAEx  
output.writeInt(nStartPos.length); /2/aMF(J  
for(int i=0;i<nStartPos.length;i++) 5=#d#dDc  
{ emrA!<w!W  
// output.writeLong(nPos); OA\] |2 :  
output.writeLong(fileSplitterFetch.nStartPos); VMJaL}J]  
output.writeLong(fileSplitterFetch.nEndPos); k%O3\q  
} ]' Ho)Q  
output.close(); OUGkam0UK  
} h. ftl2>  
catch(IOException e){e.printStackTrace ();} }KIS_krs  
catch(Exception e){e.printStackTrace ();} fXl2i]L(^B  
} C%]qK(9vvd  
I"lzOD; eI  
aTeW#:m  
//读取保存的下载信息(文件指针位置) [ @"6:tTU  
private void read_nPos() .%.7~Nu,  
{ L'aB/5_%  
try{ hp9LV2_5  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7(tsmP  
int nCount = input.readInt(); L1(-xNUo_i  
nStartPos = new long[nCount]; U{pg y#/  
nEndPos = new long[nCount]; xJ. kd Tr  
for(int i=0;i<nStartPos.length;i++) A4#F AFy  
{ N#e9w3Rli  
nStartPos = input.readLong(); U\j g X  
nEndPos = input.readLong(); u1#(~[.  
} ?(K=du  
input.close(); y6[le*T  
} ]plp.f#av  
catch(IOException e){e.printStackTrace ();} c@}t@k  
catch(Exception e){e.printStackTrace ();} >ZG$8y 'j  
} qs bo"29  
w4TQ4 Y  
'2<r{  
private void processErrorCode(int nErrorCode) NqOX);'L0  
{ (6a<{  
System.err.println("Error Code : " + nErrorCode); &$_!S!Sa/  
} +By'6?22  
<)(W7#Ks  
i}v.x  
//停止文件下载 oS9Od8  
public void siteStop() ZxT E(BQv  
{ BQg3+w:>  
bStop = true; .7b%7dQ<\  
for(int i=0;i<nStartPos.length;i++) 9609  
fileSplitterFetch.splitterStop(); DQXcf*R  
Ny$3$5/  
GQ@mQ=i  
} .lP',hn  
} VWHpfm[r%  
//负责部分文件的抓取 UdnRsp9S  
**FileSplitterFetch.java 6<fG; :  
*/ Jkbeh.  
package NetFox; e_KfnPY   
M_ %-A  
Khc^q*|C)  
import java.io.*; gVzIEE25  
import java.net.*; Tjrb.+cua  
G&1bhi52  
"uIaKb  
public class FileSplitterFetch extends Thread { YMK ![ q-  
K@cWg C  
~KkC089D  
String sURL; //File URL #m?)XB^_  
long nStartPos; //File Snippet Start Position 5toa@#Bc%  
long nEndPos; //File Snippet End Position AL3iNkEa  
int nThreadID; //Thread's ID J9]cs?`)  
boolean bDownOver = false; //Downing is over <anKw|  
boolean bStop = false; //Stop identical "H`Be  
FileAccessI fileAccessI = null; //File Access interface rg>2tgA  
F5/,S   
Bh cp=#  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ZnI15bsDx  
{ id5`YA$  
this.sURL = sURL; gz[3xH~  
this.nStartPos = nStart; J-dB  
this.nEndPos = nEnd; g([:"y?  
nThreadID = id; `=#jWZ.8m  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A7+ZY,  
} #*_!Xc9f  
^w~B]*A :"  
?-mOAHW0q  
public void run() \ DZ.#=d  
{ MSvZ3[5Io  
while(nStartPos < nEndPos && !bStop) s*yl& El/  
{ +#BOWz  
^ `Ozw^~  
Sm4BZF~!B  
try{ J({D~  
URL url = new URL(sURL); 0]c&K  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ll X `  
httpConnection.setRequestProperty("User-Agent","NetFox"); ?%Nh4+3N>  
String sProperty = "bytes="+nStartPos+"-"; [t fB*m5  
httpConnection.setRequestProperty("RANGE",sProperty); OmBz'sp:  
Utility.log(sProperty); -NN=(p!<  
(iir,Ks2C  
k"&o)*d  
InputStream input = httpConnection.getInputStream(); TK\3mrEI  
//logResponseHead(httpConnection); o68i0aFW  
T pF [-fO  
DWKQ>X6  
byte[] b = new byte[1024]; *1`X}  
int nRead; b1 w@toc  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1s=Q~*f~d  
{ !KK`+ 9/  
nStartPos += fileAccessI.write(b,0,nRead); Y 2ANt w@  
//if(nThreadID == 1) I)FFh%m<}a  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /^nIOAeE  
} OR~ui[w  
S5 q1M n  
lRg?||1ik  
Utility.log("Thread " + nThreadID + " is over!"); eZT8gKbjJ)  
bDownOver = true; jmr .gW  
//nPos = fileAccessI.write (b,0,nRead); .UL 2(0  
} >iOf3I-ATt  
catch(Exception e){e.printStackTrace ();} z6E =%-`  
} A3_p*n@  
} s~ 8 g  
<F0^+Pf/  
EA6l11{Gk1  
//打印回应的头信息 o$.#A]Flb  
public void logResponseHead(HttpURLConnection con) >{Hg+/  
{ ")uKDq  
for(int i=1;;i++) 9!Mh (KtQ  
{ (=7"zE Cq#  
String header=con.getHeaderFieldKey(i); j%nN*ms  
if(header!=null) f- 9t  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); xWzybuLp  
Utility.log(header+" : "+con.getHeaderField(header)); m- <y|3  
else a&b/C*R_  
break; NLL"~  
} r]p3DQ  
} 8N'hG,  
{ac$4#Bp[B  
<>\|hno}  
public void splitterStop() `Fr ,,Q81\  
{ -GPBX?  
bStop = true; a&8K5Z%0  
} >t cEx(  
;Y*K!iFWH  
3qe`#j  
} ^w1+b;)  
(y>N\xS9  
d[3me{Rs  
/* ,jg #^47I  
**FileAccess.java nA,=g'7S  
*//文件访问(定位,写) SQcic]Ep  
package NetFox; "73y}'  
import java.io.*; C+s/KA%  
X#$ oV#  
KUZi3\p9W>  
public class FileAccessI implements Serializable{ 0@ "'SKq  
'xqyG XI  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Zwc&4:5%  
RandomAccessFile oSavedFile; ?Xypn#OPt  
long nPos; GE!nf6>Km  
o-RZwufZ`  
[y`G p#  
public FileAccessI() throws IOException |cY HH$  
{ %;:![?M  
this("",0); .2JZ7  
} }NC$Ce  
ESV./~K  
n?r8ZDJ'  
public FileAccessI(String sName,long nPos) throws IOException (v/L   
{ ,Lp"Ia  
oSavedFile = new RandomAccessFile(sName,"rw"); }VJ>}i*  
this.nPos = nPos; ,g7O   
oSavedFile.seek(nPos); hTLf$_|P  
} tB>!1}v  
z]8Mv(eL  
s|<n7 =J  
public synchronized int write(byte[] b,int nStart,int nLen) Q;3`T7  
{ )m7%cyfC  
int n = -1; x!GDS>  
try{ g3kbsi7_:  
oSavedFile.write(b,nStart,nLen); Gpxp8[ {  
n = nLen; Q"FN"uQ}x  
} IwnDG;+Ap  
catch(IOException e) #VX]trh,  
{ }XBF#BN  
e.printStackTrace (); Qt4mg?X/  
} qWr=Oiu  
_)5E=  
45.ks.  
return n; )b1hF  
} QHO n?e  
cN&Ebn  
-r cEG!  
} q&@s/k  
SzpUCr"  
&{8:XJe*,%  
/* m=9b/Nr4  
**SiteInfoBean.java A` _dj}UF  
*/ NHyUHFY  
package NetFox; Gn 9oInY1  
eWv:wNouk  
QoxYzln  
public class SiteInfoBean { Wd;t(5Xl  
'hr_g* i  
apm%\dN  
private String sSiteURL; //Site's URL +C!GV.q[  
private String sFilePath; //Saved File's Path QYo04`Rl  
private String sFileName; //Saved File's Name WZ ?>F  
private int nSplitter; //Count of Splited Downloading File }TMO>eB'  
N@PwC(   
p}pRf@(`\  
public SiteInfoBean() .S,E=  
{//nSplitter的缺省值为5 ,4"N7_!7  
//default value of nSplitter is 5 ^?Xs!kJP  
this("","","",5); e+BZoK ^  
} Z OPK  
I=&i &6v8G  
H3$py|}lL  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A!!!7tj  
{ :|V650/  
sSiteURL= sURL; ?QffSSj[s  
sFilePath = sPath; b(N\R_IQ~  
sFileName = sName; Wx-0Ip'9  
this.nSplitter = nSpiltter; hGD@v {/  
*bp09XG  
*D%w r'!>  
} BmpAH}%T  
e]1'D  
o7E|wS  
public String getSSiteURL() P,pC Z+H  
{ #:BkDidt2v  
return sSiteURL; (Nc~l ^a  
} Vc5>I_   
^*fD  
}d; 2[fR)  
public void setSSiteURL(String value) \ejHM}w3,  
{ tm5{h{AM  
sSiteURL = value; T=YVG@fm?  
} '9u?lA^9$  
jA9uB.I,"b  
L<=Dl  
public String getSFilePath() E'4Psx9: =  
{ DQK?y=vf  
return sFilePath; [(Z(8{3i  
} ^=^\=9" b  
q n-f&R  
e bp t/q[  
public void setSFilePath(String value) oQ -m  
{ "[7-1}l  
sFilePath = value; mmJnE  
} %2dzx[s  
RdD>&D$I  
`,SL\\%u  
public String getSFileName() ,*W~M&n"m  
{ ,&@GxiU  
return sFileName; ?l%4 P5  
} |Io:D:  
U)f('zD  
bu6Sp3g  
public void setSFileName(String value) A{;"e^a-^l  
{ jC[_uG  
sFileName = value; Q(-&}cY  
} 8>WA5:]v  
5QK%BiDlr  
 &ox  
public int getNSplitter() +pG+ xI  
{ t[+bZUS$~  
return nSplitter; "9'3mmZm=?  
} N{bg-%s10i  
db,?b>,EE  
8<}=f4vUj5  
public void setNSplitter(int nCount) AJ6l#j-  
{ Kw"e4 a  
nSplitter = nCount; rzHBop-8  
} N9|J\;fzT  
} .?s jr4   
o@gceZuk  
#pPOQv:~  
/* (bv{1 7K  
**Utility.java :@jctH~  
*/ %ZD]qaU0  
package NetFox; P\K#q%8  
DgcS@N  
 'V^M+ng  
public class Utility { tf7HhOCYX  
Gn4b*Y&M]3  
(N&i4O-I  
public Utility() py7Zh%k  
{ !HU$V9C  
YK{J"Kof  
'cc8 xC  
} $"NH{%95}  
hfI=9x/  
//线程睡眠 x&DqTX?b,  
public static void sleep(int nSecond) 6bUP]^d  
{ 0,~s0]h0V  
try{ sAU%:W{  
Thread.sleep(nSecond); & 'i_A%V  
} [- 92]  
catch(Exception e) 3 .#L  
{ w;}5B~).  
e.printStackTrace (); Nb:j]U  
} AJ>E\DK0]  
} n\D/WLvM  
`XE>Td>Bs  
//日志 \Y"S4<"R  
public static void log(String sMsg) 0 cKsGDm  
{ 2;T?ry7  
System.err.println(sMsg); WqefH{PB  
} Uf+y$n-  
TYD( 6N  
!m:WoQ/  
public static void log(int sMsg) ;"IWm<]h;-  
{ Uv[a ~'  
System.err.println(sMsg); Hy :x.'i  
} $+J39%Y!^  
} /9kxDbj  
XdThl  
7#+Ih-&EQ  
/* ]tu OWR  
**TestMethod.java M887 Q'HSi  
*/ k-3;3Mq  
package NetFox; aNKw.S>  
5@1h^w v  
*JX$5bZsI  
public class TestMethod { &Qda|  
N LpKh1g  
SaGI4O_\s  
public TestMethod() tH;9"z# ~  
{ ///xx/weblogic60b2_win.exe %8I^&~E1  
try{ l-W)? d  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); pSC{0Y$g  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A4(L47^  
SiteFileFetch fileFetch = new SiteFileFetch(bean); XM!oN^  
fileFetch.start(); "Cxj_V@\  
} 16eP7s  
catch(Exception e){e.printStackTrace ();} )|v  du  
t)8c rX}P  
j%3 $ytf|p  
} Tx&H1  
S+KKGi_e  
*0,*F~n  
public static void main(String[] args) "k + :!D  
{ :T$}@& -  
new TestMethod(); X~m57 b j  
} :CM-I_6  
} 9$v\D3<Z  
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