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http断点续传简单实现(java)

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/*  ?Y(  
**SiteFileFetch.java m9 h '!X<  
*/ oJ74Mra  
package NetFox; $ Habhw  
import java.io.*; jx: IK  
import java.net.*; w&p+mJL.  
3 jZMXEG)  
4b8G 1fm  
public class SiteFileFetch extends Thread { C0wtMD:G  
~]?:v,UIm(  
#S}orWj  
SiteInfoBean siteInfoBean = null; //文件信息Bean VI0wul~M  
long[] nStartPos; //开始位置 v ,8;: sD  
long[] nEndPos; //结束位置 >t+U`6xK  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 =@HS  
long nFileLength; //文件长度 j9p6 rD  
boolean bFirst = true; //是否第一次取文件 #De>EQ%  
boolean bStop = false; //停止标志 #,%bW[L<N  
File tmpFile; //文件下载的临时信息 !+GYu;_  
DataOutputStream output; //输出到文件的输出流 T8XrmR&?PX  
C= ~c`V5>r  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) tn]nl!_@  
public SiteFileFetch(SiteInfoBean bean) throws IOException U'fP  
{ 7'G;ijx  
siteInfoBean = bean; J2bvHxb Rd  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ]juPm8eF  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); X3.zNHN5  
if(tmpFile.exists ()) Fc~G*Gz~Z|  
{ nf.Ox.kM)  
bFirst = false; Ar`+x5  
read_nPos(); cHjQwl  
} Pe`(9&iT.  
else C8U3+ s  
{ T+kV~ w{  
nStartPos = new long[bean.getNSplitter()]; fkA+:j~z_  
nEndPos = new long[bean.getNSplitter()]; AI|vL4*Xd  
} "4N&T#  
=+zDE0Qs  
smP4KC"I(d  
VmS_(bM  
} |7qt/z  
iQ'*QbP'Z  
Q_5 l.M/9]  
public void run() Qs6<(zaqkt  
{ -$Oh.B`i  
//获得文件长度 3_(_yEKx  
//分割文件 <DF3!r  
//实例FileSplitterFetch qE[S>/R"  
//启动FileSplitterFetch线程 3JnpI,By  
//等待子线程返回 l2D*b93  
try{ bJ ~H  
if(bFirst) Y t(D  
{ 9]4Q@%  
nFileLength = getFileSize(); 0U '"@A \  
if(nFileLength == -1) lSxb:$g  
{ Br1R++]  
System.err.println("File Length is not known!"); {)[o*+9  
} pSs*Z6c)@  
else if(nFileLength == -2) pgU [di  
{ ij" ~]I  
System.err.println("File is not access!"); ]PXM;w  
} A;oHji#*  
else ci0A!wWD  
{ Q]ersA8 V>  
for(int i=0;i<nStartPos.length;i++) |Y9>kXMl  
{ F.9}jd{  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); hZ&KE78?  
} @@65t'3S  
for(int i=0;i<nEndPos.length-1;i++) +7_qg i7:  
{ iC"iR\Qu  
nEndPos = nStartPos[i+1]; ){^J8]b7#  
} WtT;y|W  
nEndPos[nEndPos.length-1] = nFileLength; 8=8 hbdy;  
} lx)^wAO4  
} @X==[gQ  
q+ax]=w  
MpV<E0CmE  
//启动子线程 /bo}I-<2  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~ao:9 ynY  
for(int i=0;i<nStartPos.length;i++) YQBLbtn6(  
{ >3 o4 U2  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6(n0{A  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), djd/QAfSC  
nStartPos,nEndPos,i); )U/jD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VYk:c`E  
fileSplitterFetch.start(); J9^NHU  
} #Hw|P  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Cf% qap#  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); YT\`R  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", U3(+8}Q  
nEndPos = " + nFileLength); =[B\50]  
// fileSplitterFetch[nPos.length-1].start(); I/E9:  
7^L  
) .~ "  
//等待子线程结束 N /4E ~^2  
//int count = 0; 55Ss%$k@  
//是否结束while循环 `4Yo-@iVP  
boolean breakWhile = false; 9LR=>@Z  
C6!F6Stn]g  
Et=Pr+Q{c  
while(!bStop) JZ5k3#@e  
{ N\{"&e  
write_nPos(); W06aj ~7Z  
Utility.sleep(500); ?cU,%<r  
breakWhile = true; |]\zlH"w  
,i>`Urd  
Bf{u:TCK  
for(int i=0;i<nStartPos.length;i++) = Xgo}g1  
{ "Q?+T:D8|  
if(!fileSplitterFetch.bDownOver) HDe\Oty_  
{  a_?sJ  
breakWhile = false; |T:R.=R$~  
break; -|>~I#vY  
} G m~ ./-  
} 5.rAxdP  
if(breakWhile) $dC`keQM>9  
break; GppCrQ%Ra|  
=L W!$p  
c_8&4  
//count++; <WXVUEea  
//if(count>4) e~)[I!n  
// siteStop(); 3>O|i2U  
} %:3XYO.w-  
09kR2(nsW/  
ww2mL <B  
System.err.println("文件下载结束!"); +%dXB&9x|Z  
} >0^<<=m  
catch(Exception e){e.printStackTrace ();} EX,>V,.UV  
} wh$bDT Cj  
U>S  
q}U+BTCZ  
//获得文件长度 7|,L{~  
public long getFileSize() VfU"%0x  
{ (r|m&/  
int nFileLength = -1; 05d0p|},  
try{ F8pA)!AH  
URL url = new URL(siteInfoBean.getSSiteURL()); =uP? ?E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t"=5MaQk-  
httpConnection.setRequestProperty("User-Agent","NetFox"); )+ .=z  
3?Pg ;  
mjeJoMvN)H  
int responseCode=httpConnection.getResponseCode(); `Ba]i)!  
if(responseCode>=400) #g{R+#fm  
{ -FZC|[is  
processErrorCode(responseCode); fi?4!h  
return -2; //-2 represent access is error FnvpnU",  
} GJ9>i)+h;  
zWY988fX0  
Exb64n-_=  
String sHeader; R%UTYRLUn  
Gwd38  
#p}GWS)  
for(int i=1;;i++) O}M-6!%<,  
{ +,e#uuj$p  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4@9Pd &I  
//Utility.log(in.readLine()); =j.TDv'^nd  
sHeader=httpConnection.getHeaderFieldKey(i); t3<MoDe7`r  
if(sHeader!=null) 3$?6rMl@y  
{ cBxGGggB  
if(sHeader.equals("Content-Length")) !M^O\C)  
{ Tmzbh 9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nI:M!j5s`  
break; 5(>=};r+  
} b RAD_  
} /,\V}`Lx"  
else uw;Sfx,s  
break; VF`!ks  
} v,w af`)J  
} Giyh( DL  
catch(IOException e){e.printStackTrace ();} yE}\4_0I/  
catch(Exception e){e.printStackTrace ();} &8$v~  
T$;S   
';C'9k<P:  
Utility.log(nFileLength); 25>R^2,LiE  
* %D_\0;  
%"WENa/t  
return nFileLength; ifD WN*k6  
} '=dQ$fs  
h;V 4|jM  
7FC!^)x1  
//保存下载信息(文件指针位置) ,L ig6Z`  
private void write_nPos() |ADf~-AY  
{ wJC[[_"3 I  
try{ P$E iD+5#z  
output = new DataOutputStream(new FileOutputStream(tmpFile)); jVff@)_S  
output.writeInt(nStartPos.length); lV\iYX2#  
for(int i=0;i<nStartPos.length;i++) 9nFL70  
{ VZ9 p "  
// output.writeLong(nPos); N/tcW  
output.writeLong(fileSplitterFetch.nStartPos); E)-;sFz  
output.writeLong(fileSplitterFetch.nEndPos); )r e<NE&M  
} f,G*e367:  
output.close(); [qc1 V%g  
} ~F"S]  
catch(IOException e){e.printStackTrace ();} j iKHx_9P  
catch(Exception e){e.printStackTrace ();} ]?6wU-a  
} 8iIp[9~=  
/.]u%;%r[  
 2%@tnk|@  
//读取保存的下载信息(文件指针位置) &5W;E+Pub  
private void read_nPos() T}fo  
{ &gCGc?/R#  
try{ P~a@{n*8  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q(& @ra!{  
int nCount = input.readInt(); _dKMBcl)E  
nStartPos = new long[nCount]; 8T1`9ITl:  
nEndPos = new long[nCount]; T5:Q_o]  
for(int i=0;i<nStartPos.length;i++) |Y3w6!$  
{ XvI~"}  
nStartPos = input.readLong(); 9pLe8D  
nEndPos = input.readLong(); x Lan1V  
} OAXA<  
input.close(); IxbQ6  
} 7_\G|Zd  
catch(IOException e){e.printStackTrace ();} !v8R(  
catch(Exception e){e.printStackTrace ();} $Cz2b/O  
} 4R'CL N |t  
a>47k{RSzE  
m.lR]!Y=w  
private void processErrorCode(int nErrorCode) ;W- A2g  
{ 2 7)If E  
System.err.println("Error Code : " + nErrorCode); gmVN(K}SR5  
} a2P)@R  
;EBKzB  
{o~TbnC  
//停止文件下载 _r:Fmn_%-  
public void siteStop() ad}8~6}_&  
{ 71{Q#%5U~  
bStop = true; )U~|QdZ  
for(int i=0;i<nStartPos.length;i++) %9cT#9!7  
fileSplitterFetch.splitterStop(); W&hW N9iR  
m7^f%<l  
, 5W7a  
} 8?Rp2n*o  
} v]EMJm6d|  
//负责部分文件的抓取 7Fj8Mp|  
**FileSplitterFetch.java Y_CYx  
*/ oJA_" xp  
package NetFox; d*8*9CpO:  
ny KfM5s_  
|enLv12Gm  
import java.io.*; w"{DLN[Qw  
import java.net.*; LK}g<!o(  
6Z|h>H5 a  
f2e;N[D  
public class FileSplitterFetch extends Thread { D$>!vD'  
8i',~[  
I8XP`Ccq  
String sURL; //File URL qur2t8gnxq  
long nStartPos; //File Snippet Start Position lie,A  
long nEndPos; //File Snippet End Position f#z:ILG=  
int nThreadID; //Thread's ID Ch]d\GM  
boolean bDownOver = false; //Downing is over e@P(+.Ke  
boolean bStop = false; //Stop identical ~cc }yDe  
FileAccessI fileAccessI = null; //File Access interface Y"lEMY  
ps'_Y<@  
Krae^z9R  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ao\P|K9MyL  
{ YrnC'o`  
this.sURL = sURL; DgT]Nty@b  
this.nStartPos = nStart; 5Npxs&Ea  
this.nEndPos = nEnd; a,w|r#x]  
nThreadID = id; ;`oK5  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;t0 q ?9  
} NVRzthg%c_  
T +vo)9w  
x'g4DYl  
public void run() -J3~j kf  
{ (RFH.iX  
while(nStartPos < nEndPos && !bStop) %*Ex2we&  
{ 4s 7 RB  
pg%(6dqK4  
,ayEZ#4.m  
try{ =mXC,<]  
URL url = new URL(sURL); $wAR cS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ba[,9l[  
httpConnection.setRequestProperty("User-Agent","NetFox"); iyn9[>j e  
String sProperty = "bytes="+nStartPos+"-"; Xf4~e(O  
httpConnection.setRequestProperty("RANGE",sProperty); =803rNe  
Utility.log(sProperty); +j{Cfv$do  
!JXiTI!  
1 !_p  
InputStream input = httpConnection.getInputStream(); 1r=cCM  
//logResponseHead(httpConnection); A,F~*LXm  
:(]fC~G~  
p q`uB  
byte[] b = new byte[1024];  ,]EhDW6  
int nRead; F `7 v  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g ` s|]VNt  
{ 0!,uo\`  
nStartPos += fileAccessI.write(b,0,nRead); =.z;:0]'n  
//if(nThreadID == 1) KRL.TLgq)  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j{lurb)y  
} Z5Lmg  
fHd[8{;P:  
%rrA]\C'  
Utility.log("Thread " + nThreadID + " is over!"); HF0G=U}i  
bDownOver = true; l Xa/5QKC  
//nPos = fileAccessI.write (b,0,nRead); wF`Y ,@  
} |RL#BKC`  
catch(Exception e){e.printStackTrace ();} t.8r~2(?  
} V22z-$cb  
} sQ`G'<!  
6C VH)=%  
d Gp7EB`  
//打印回应的头信息 jRjeL'"G  
public void logResponseHead(HttpURLConnection con) "r46Rfa  
{ RiQ ]AsTtl  
for(int i=1;;i++) %)7t2D  
{ HaVhdv3L  
String header=con.getHeaderFieldKey(i); jMn,N9Mf  
if(header!=null) yMWh#[phH  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e' M&Eh  
Utility.log(header+" : "+con.getHeaderField(header)); Imv#7{ndq  
else @$jV"Y  
break; cTGd<  
} Os<E7l zqO  
} F6}RPk\=i  
t~(jA9n  
p=:Vpg<!  
public void splitterStop() ZGZNZ}~#  
{ #DgHF*GG+>  
bStop = true; e%cTFwX?n  
} 3SIq od;%  
+4-T_m/W/  
U,P>P+\@  
} Ms|c" ?se  
'yPKQ/y$x  
l(NQk> w  
/* XSC=qg$  
**FileAccess.java Z$/76  
*//文件访问(定位,写) d~~kJKK  
package NetFox; e4` L8  
import java.io.*; 3A`Gx#  
YTyrX  
5;}W=x^$a  
public class FileAccessI implements Serializable{ EQ273sdK  
i*=~m O8E  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 os{ iY  
RandomAccessFile oSavedFile; ol"|?*3q  
long nPos; U1r]e%df)  
~Fuq{e9`  
XY| y1L 3[  
public FileAccessI() throws IOException 44} 5o  
{ jM\{*!7b  
this("",0); &1Ndi<Y^  
} _94 W@dW  
eMRH*MyD  
0FOB5eBR  
public FileAccessI(String sName,long nPos) throws IOException ! $$>D"  
{ sm-[=d%@L  
oSavedFile = new RandomAccessFile(sName,"rw"); 83c2y;|8  
this.nPos = nPos; QP%_2m>yhl  
oSavedFile.seek(nPos); r+bGZ  
} M?lh1Yu"  
}R}+8  
#Kb /tOp1  
public synchronized int write(byte[] b,int nStart,int nLen) >S I'Q7k  
{ M,fL(b;2  
int n = -1; n.+'9Fj  
try{ wS}c \!@<,  
oSavedFile.write(b,nStart,nLen); o^/ #i`)  
n = nLen; |@AXW   
} Y_CVDKdcY  
catch(IOException e) V^,gpTyv*  
{ X8*g#lO?  
e.printStackTrace (); -F7F 6!s  
} w5 .^meU  
G[mqLI{q  
#r9+thyC  
return n; <(KCiM=E$  
} -iiX!@  
_uO$=4Sd  
,m<YS MKX  
} AU\=n,K7  
*Y(59J2  
Y]([K.I=  
/* 1w=.vj<d8  
**SiteInfoBean.java NVb}uH*i  
*/ 2{h2]F  
package NetFox; 8b?nr;@  
x/O;8^b  
SxY z)aF~  
public class SiteInfoBean { {<ShUN  
Rv&"h_"t  
jg?UwR&  
private String sSiteURL; //Site's URL 4 "2%mx:  
private String sFilePath; //Saved File's Path bX$z)]KKu  
private String sFileName; //Saved File's Name U"7o;q  
private int nSplitter; //Count of Splited Downloading File X_2N9$},  
)P(S:x'b0  
K(?V]Mxl6  
public SiteInfoBean() Q("m*eMRt  
{//nSplitter的缺省值为5 uU 7 <8G  
//default value of nSplitter is 5 WPRk>j  
this("","","",5); hq7f"`  
} G0 EXgq8  
P7-k!p"  
BsFO]F5mmX  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9:{<:1?  
{ I#MPJ@*WT  
sSiteURL= sURL; :Tpf8  
sFilePath = sPath; z[f]mU  
sFileName = sName; *W8n8qG%T  
this.nSplitter = nSpiltter; ZhY{,sy?QO  
0i\>(o  
Sl8+A+  
} BHY-fb@R]H  
M Z"V\6T]  
6 >)fNCe`  
public String getSSiteURL() hA ){>B<;  
{ o:#jvi84F  
return sSiteURL; eF%M2:&c;  
} SPV+ O{  
PaSwfjOnqr  
MQP9^+f)O?  
public void setSSiteURL(String value) Gt*<Awn8  
{ :z8/iD y  
sSiteURL = value; zh2<!MH  
} f$>_>E  
q(qm3OxYo  
c= t4 gf  
public String getSFilePath() c6F?#@?   
{ }p?,J8=-  
return sFilePath; l?)>"^  
} Wq3PN^  
KRxJ2  
G|jHic!  
public void setSFilePath(String value) >l 0aME@-0  
{ m^oG9&";  
sFilePath = value; LhAN( [  
} 1vq2`lWpx  
9C \}bT  
]lA}5  
public String getSFileName() 2@MpWj4  
{ rS>.!DiYr,  
return sFileName; 1#N`elm  
} 7D<Aa?cv_l  
"=Z=SJ1D  
h~Ir= JV  
public void setSFileName(String value) |$/#,Dv7  
{ drAJ-ii  
sFileName = value; !!L'{beF  
} h.?<( I  
jlb8<xIC]  
_i ztQ78  
public int getNSplitter() p8 S~`fjV  
{ N_ ODr]L  
return nSplitter; Dl.< (/  
} Vb? wwx7=  
/HUT6B  
2(!W 9#]  
public void setNSplitter(int nCount) fP<== DK  
{ }N9PV/a  
nSplitter = nCount; %S^ke`MhF  
} 5:38}p9`  
} 7d.H 8C2  
$E[O}+L$#  
qf K gNZ  
/* .~I:Hcf/  
**Utility.java :Jyr^0`J  
*/ 8o:h/F  
package NetFox; (;g/wb:  
n5"i'o{w  
hD#Mhy5h  
public class Utility { ~<u\YIJ  
c@,1?q1bv  
roZn{+f  
public Utility() F$i50s  
{ WS&a9!3;  
CHS}tCfos>  
y=9fuGL6  
} 9+(6 /<  
KOR*y(*8  
//线程睡眠 d3a!s  
public static void sleep(int nSecond) 0<uL0FOT  
{ KYkS ^v  
try{ rk %pA-P2  
Thread.sleep(nSecond); %l%ad-V  
} ih("`//nP  
catch(Exception e) a:P+HU:  
{ %d:cC:`  
e.printStackTrace (); vZQraY nJ  
} R,.qQF\*  
} yuq o ^i  
lw8t#_P  
//日志 Jm=3 %H  
public static void log(String sMsg) @=g{4(zR ^  
{ DCa=o  
System.err.println(sMsg); ;]R5:LbXS  
} KKk<wya&O  
F+5 5p8  
, MqoX-+  
public static void log(int sMsg) rLeQB p'  
{ 43=)akJi  
System.err.println(sMsg); V,Bol(wY  
} a-#$T)mmfj  
} L   
dM}c-=w`  
u=PLjrB~}  
/* 8fQfu'LyjY  
**TestMethod.java >`WQxkpy  
*/ - ]/=WAOK  
package NetFox; Wt5pK[JV  
>t9DI  
2ETv H~23  
public class TestMethod { MYJMZ3qBi  
1e9~):C~W  
KWYjN h#*  
public TestMethod() 3it*l-i\  
{ ///xx/weblogic60b2_win.exe ,y0 &E8Z  
try{ kxrYA|x  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SPe%9J+  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); cAx$W6S  
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,ZYPffu<*  
fileFetch.start(); }]1C=~lC  
} nql{k/6  
catch(Exception e){e.printStackTrace ();} 3 %BI+1&T_  
F1}d@^K 7d  
o]]tH  
} \ %xku:  
a$iDn_{  
D0_CDdW%7  
public static void main(String[] args) T#e|{ZCbq  
{ N3Q .4? z9  
new TestMethod(); Z>/ *q2  
} CZ^ ,bad  
} ]T40VGJ:h  
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