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http断点续传简单实现(java)

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/* m=}kGzIY4  
**SiteFileFetch.java ix$+NM<n  
*/ Jp,ohVRNq  
package NetFox; D l"y|  
import java.io.*; { _ 1q`5o  
import java.net.*; W&p-Z"=)  
j?8E >tM  
(8EZ,V:  
public class SiteFileFetch extends Thread { q&W#nWBV  
H+: $ 7;  
5?I]\Tb  
SiteInfoBean siteInfoBean = null; //文件信息Bean Ic r'l$PE  
long[] nStartPos; //开始位置 hi ]+D= S  
long[] nEndPos; //结束位置 MBwp{ET!p  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 Fvv6<E  
long nFileLength; //文件长度 XSD7~X/:  
boolean bFirst = true; //是否第一次取文件 Xg%zE  
boolean bStop = false; //停止标志 [%h^qJ  
File tmpFile; //文件下载的临时信息 }5S2v+zE  
DataOutputStream output; //输出到文件的输出流 4Fz^[L}[  
67sb D<r  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) )1]C%)zn  
public SiteFileFetch(SiteInfoBean bean) throws IOException @rJ#Dr  
{ t)v#y!Ci"  
siteInfoBean = bean; sP&E{{<QTF  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); Z'fy9  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); zf S<X  
if(tmpFile.exists ()) Cn{UzSKfs  
{ HL!-4kN <$  
bFirst = false; x)GoxH~#  
read_nPos(); #IXQ;2%E  
} [ z&y]~  
else }0!\%7-Q  
{ 8t7hN?,t  
nStartPos = new long[bean.getNSplitter()]; AV&eg e  
nEndPos = new long[bean.getNSplitter()]; &#)3v8  
} dZYS5_wr  
nh8h?&q|  
]v#T'<Nl  
6zI?K4o  
} L_A|  
TfxKvol'  
3)eeUO+  
public void run() "vJADQ4F  
{ Nyo6R9^  
//获得文件长度 8uu:e<PLv  
//分割文件 >\i{,F=U7  
//实例FileSplitterFetch 0- #ct1-  
//启动FileSplitterFetch线程 rms&U)?  
//等待子线程返回 [AGm%o=)  
try{ REsThB  
if(bFirst) ofi']J{R  
{ g 08 `=g  
nFileLength = getFileSize(); p75w^  
if(nFileLength == -1) b"Ulc}$/&  
{ Vw#07P#A  
System.err.println("File Length is not known!"); 3 (<!pA  
} lWdE^-  
else if(nFileLength == -2) k+i=0 P0mf  
{ -`gC?yff:  
System.err.println("File is not access!");  K A<  
} fU8;CZnx  
else m|y]j4  
{ *X>rvAd3  
for(int i=0;i<nStartPos.length;i++) lg=[cC2  
{ vSyN_AB?$  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); $C>EnNx  
} XNl!(2x'pb  
for(int i=0;i<nEndPos.length-1;i++) N; hq  
{ @s[bRp`gd  
nEndPos = nStartPos[i+1]; *GDU=D}  
} V]8fn MH  
nEndPos[nEndPos.length-1] = nFileLength; VT9$&\)>O  
} ULJI` I|m  
} YA|*$$  
EHb:(|UA%8  
p$=3&qR 6  
//启动子线程 FStfGN  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +Q '|->#  
for(int i=0;i<nStartPos.length;i++) o4J K$%  
{ %DN& K  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zz9.OnZ~  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?|L)!LYx  
nStartPos,nEndPos,i); .xD-eWw3R  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;F:(5GBi  
fileSplitterFetch.start(); y>o#Hq&qM  
} 5_O.p3$tV  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eu4x{NmQ  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hN}X11  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &sKYO<6K }  
nEndPos = " + nFileLength); '=ZE*nGC  
// fileSplitterFetch[nPos.length-1].start(); FD6|>G  
x=Ru@nK;  
(0][hdI~B  
//等待子线程结束 oT_,k}LIX  
//int count = 0; OW.ckYt%  
//是否结束while循环 "K@os<  
boolean breakWhile = false; v ;9s  
W,<Vr2J[  
v3/cNd3  
while(!bStop) QO k%Q$^G  
{ 2D!'7ZD  
write_nPos(); 5M(?_qj  
Utility.sleep(500); FxUH ?%w  
breakWhile = true; 3Q#VD)  
B845BSmh  
JrQN-e!  
for(int i=0;i<nStartPos.length;i++) s)N1@RBR  
{ a0n F U  
if(!fileSplitterFetch.bDownOver) sv[)?1S  
{ w_-{$8|  
breakWhile = false; AV'>  
break;  <O*q;&9  
} !1l2KW<be  
} dfrq8n]  
if(breakWhile) !!QMcx_C#/  
break; EmH{G  
ucn aj|  
hZFbiGQr\  
//count++; !pN,,H6Y  
//if(count>4) X3"V1@-i4$  
// siteStop(); mA4v  4z  
} Sb`>IlT\#  
"<&F=gV  
PaZFM  
System.err.println("文件下载结束!"); a@7we=!  
} qmK!d<4  
catch(Exception e){e.printStackTrace ();} l5R H~F  
} %'>. R  
$a-~ozr`C  
`KL`^UqR  
//获得文件长度 8'?e4;O  
public long getFileSize() S)~h|&A(  
{ =DtM.oQ>  
int nFileLength = -1; xJ3#k;  
try{ [$./'-I]  
URL url = new URL(siteInfoBean.getSSiteURL()); E`X+fJx  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EfyF]cYL  
httpConnection.setRequestProperty("User-Agent","NetFox"); dRu@5 :BP  
NLdUe32A  
>S~#E,Tg  
int responseCode=httpConnection.getResponseCode(); "#9WF}  
if(responseCode>=400) WOwIJrP  
{ 8Yj(/S3y  
processErrorCode(responseCode); <Ei|:m  
return -2; //-2 represent access is error We9mkwK7C  
} fEpY3od  
ja:%j&:  
1{,WY(,c  
String sHeader; o`#;[  
%xg"e O2x  
[Ea5Bn;~!  
for(int i=1;;i++) 7' 6m;b~F  
{ Yd,*LYd2EL  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u'N'<(\k  
//Utility.log(in.readLine()); 9 ROKueP  
sHeader=httpConnection.getHeaderFieldKey(i); ~MXPiZG?  
if(sHeader!=null) H7{ 6t(0j  
{ qH-dT,`"{  
if(sHeader.equals("Content-Length")) ;hg]5r_  
{ jf})"fz-*  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CSD8?k]2  
break; "ex? #qD&  
} UyJ5}fBJ  
} |mK d5[$  
else 9]S}m[8k  
break; ;~@2YPj  
} P8TiB  
} Qn<< &i~  
catch(IOException e){e.printStackTrace ();} 0h; -Yg  
catch(Exception e){e.printStackTrace ();} Ii"cDH9  
rbJ-vEzo.#  
l&C%oW  
Utility.log(nFileLength); O}D]G%,m  
_h.[I8xgYG  
eLt6Hg)s`9  
return nFileLength; hsl Js^  
} W9u (  
#ucOjdquq  
SKYS6b  
//保存下载信息(文件指针位置) z cA"\  
private void write_nPos() B4{A(-Tc  
{ ]=pEs6%O3  
try{ U %KoG-#  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8gx^e./  
output.writeInt(nStartPos.length); `j<'*v zo  
for(int i=0;i<nStartPos.length;i++) ?5->F/f&  
{ uxR_(~8  
// output.writeLong(nPos); e0hT  
output.writeLong(fileSplitterFetch.nStartPos); LN7;Yr  
output.writeLong(fileSplitterFetch.nEndPos); rL%xl,cn<  
} lI D5mg3 1  
output.close(); PanyN3rC*  
} CUYp(GU  
catch(IOException e){e.printStackTrace ();} ."h;H^5  
catch(Exception e){e.printStackTrace ();} ;z[yNW8  
} mMa7Eyaf  
=XYfzR  
eDy}_By^  
//读取保存的下载信息(文件指针位置) i=SX_#b^  
private void read_nPos() -nU_eDy  
{ E(S}c*05O  
try{ aEgzQono  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H!xBFiOH$n  
int nCount = input.readInt();  D}_\oE/n  
nStartPos = new long[nCount]; bhg"<I  
nEndPos = new long[nCount]; Oo#wPT;1^(  
for(int i=0;i<nStartPos.length;i++) #7g~U m%p  
{ &'(:xjN  
nStartPos = input.readLong(); S4 tdW A  
nEndPos = input.readLong(); zKI(yC  
} ^beW*O!  
input.close(); xxedezNko  
} tBf u{oC  
catch(IOException e){e.printStackTrace ();} CqF< BE  
catch(Exception e){e.printStackTrace ();} OCX?U50am  
} $y`|zK|G-  
7&+Gv6E  
20K<}:5t1  
private void processErrorCode(int nErrorCode) pM4 j=F  
{ 2/h Mx-  
System.err.println("Error Code : " + nErrorCode); "cti(0F-d  
} TX 12$p\  
n ,H;PB  
)"q2DjfX*  
//停止文件下载 :1A Ound  
public void siteStop() ^91k@MC  
{ L6',s4  
bStop = true; z?cRsqf  
for(int i=0;i<nStartPos.length;i++) }]f)Fz  
fileSplitterFetch.splitterStop(); .&L#%C  
0tl  
*ZY{^f  
} K;YK[M1!  
} )~WxNn3rx  
//负责部分文件的抓取 8IVKS>  
**FileSplitterFetch.java jIEK[vJ`  
*/ aeg5ij-]u@  
package NetFox; TpnkJygIm  
T$k) ^'  
=JEnK_@?K\  
import java.io.*; 0$P40 7  
import java.net.*; 3L#KHTM  
RJGf@am&  
9m8`4%y=  
public class FileSplitterFetch extends Thread { kH{axMNc  
8XTVpf4  
BV7GzJ2([{  
String sURL; //File URL }-Zfl jj  
long nStartPos; //File Snippet Start Position ;}:"[B3$  
long nEndPos; //File Snippet End Position 6KV&E8Gn  
int nThreadID; //Thread's ID (?~F}u v  
boolean bDownOver = false; //Downing is over cU*7E39  
boolean bStop = false; //Stop identical *BSL=8G{  
FileAccessI fileAccessI = null; //File Access interface Kr8p:$D};  
U}Fk%Jj  
bFXCaD!{G  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8rNxd=!  
{ b4PK  
this.sURL = sURL; "n-xsAG  
this.nStartPos = nStart; w2V E_  
this.nEndPos = nEnd; n_2 LkW<?  
nThreadID = id; 4rdrl  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @V u[Tg}J  
} JPzPL\  
.8~ x;P6  
3Ab$  
public void run() J>v>6OC6i  
{ 1'B?f# s  
while(nStartPos < nEndPos && !bStop) 4"=pcHNV  
{ I2Q?7p  
Q{kuB+s  
Vi-@z;k  
try{ |@|D''u>6  
URL url = new URL(sURL); 4B pm{b  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6>%NL"* ]  
httpConnection.setRequestProperty("User-Agent","NetFox"); .{>-.&  
String sProperty = "bytes="+nStartPos+"-"; fE}}>  
httpConnection.setRequestProperty("RANGE",sProperty); _RVXE  
Utility.log(sProperty); %LmB`DqZ  
AkC\CdmA  
/n=/WGl  
InputStream input = httpConnection.getInputStream(); }]@ "t)"  
//logResponseHead(httpConnection); jqmP^ZS  
?yh.*,dgi  
YJ`>&AJ  
byte[] b = new byte[1024]; |Dli6KN  
int nRead; LYv2ll`XP  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h2K  
{ l6O(+*6Us  
nStartPos += fileAccessI.write(b,0,nRead); #=m5*}=  
//if(nThreadID == 1) hNfL /^w  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #+ =afJ  
} ;pq4El_  
v\u+=}r l  
Yr@@ty  
Utility.log("Thread " + nThreadID + " is over!"); .kV/ 0!q?  
bDownOver = true; g5`YUr+3?h  
//nPos = fileAccessI.write (b,0,nRead); WOoVVjMM  
} #,C{?0!  
catch(Exception e){e.printStackTrace ();} 0KEl+  
} fN;y\!q5  
} @wz7jzMi  
mmti3Y  
l-rI|0D#  
//打印回应的头信息 |ESe=G  
public void logResponseHead(HttpURLConnection con) IYPI5qCR  
{ 6zSN?0c  
for(int i=1;;i++) .v'8G)6g  
{ PeZ=ONY5  
String header=con.getHeaderFieldKey(i); >EG;2]M&  
if(header!=null) b9Nw98`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s RB8 jY  
Utility.log(header+" : "+con.getHeaderField(header)); _1QNO#X  
else >FO=ioNY  
break; ygG9ht  
} ektFk"W3A\  
} IAQ=d4V&  
iuRXeiG8  
+`xp+Q  
public void splitterStop() bK7DGw`1  
{ 3dfSu'  
bStop = true; +{&g|V  
} L[efiiLh$  
2*N# %ZUX  
'=xl}v  
} w1Kyd?~%]  
~j_H2+!  
dx#N)?  
/* $U1'n@/J  
**FileAccess.java ^;e`ZtcI  
*//文件访问(定位,写) /on p<u  
package NetFox; Fwtwf{9I  
import java.io.*; ~Km8 -b(&  
Z2r\aZ-d`  
OpfFF;"A'  
public class FileAccessI implements Serializable{ (s~hh  
snrfHDhUw  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;6Z?O_zp4  
RandomAccessFile oSavedFile; SJfsFi?n  
long nPos; -M:.D3,L  
-Q/Dbz#-  
; 1WclQ!(  
public FileAccessI() throws IOException gNJ\*]SY  
{ $k dfY'u  
this("",0); FM5$83Q  
} - >2ej4C  
se-}d.PwL  
6%>0g^`)9Y  
public FileAccessI(String sName,long nPos) throws IOException q\\J9`Q$J  
{ gDH x+"?  
oSavedFile = new RandomAccessFile(sName,"rw"); K4KmoGb  
this.nPos = nPos; "+Kr1nW  
oSavedFile.seek(nPos); +oc}kv,h]  
} Wr;)3K  
gS!M7xy  
_oWenF  
public synchronized int write(byte[] b,int nStart,int nLen) Jx_4:G  
{ wI:oe`?H  
int n = -1; W'[!4RQL  
try{ ;:cM^LJ  
oSavedFile.write(b,nStart,nLen); d-4u*>  
n = nLen; HO' HkVA  
} 3WhJ,~o-y  
catch(IOException e) DwI)?a_+  
{ 6*%lnd+_  
e.printStackTrace (); D:f#  
} WH!<Z=#c}  
]l4\/E W6  
h<uQ~CQg  
return n; R!`#pklB  
} 9P]TIV.  
.Xr_BJ _  
{\k9%2V*+  
} Mc.KLz&,FC  
~"(1~7_  
`g#\ Ws  
/* E:7vm@+  
**SiteInfoBean.java g wk\[I`;  
*/ :=* -x  
package NetFox; V[% r5!83H  
0pu'K)Rb  
0-QkRr_ I  
public class SiteInfoBean { ^b4o 0me  
6rk/74gI,a  
KxvT}"k  
private String sSiteURL; //Site's URL +_+_`q>]  
private String sFilePath; //Saved File's Path ym:JtI69   
private String sFileName; //Saved File's Name 4;_.|!LN  
private int nSplitter; //Count of Splited Downloading File Q)v8hNyUmA  
sQR;!-j  
] O 2_&cs  
public SiteInfoBean() T_r[#j  
{//nSplitter的缺省值为5 *rWE.4=&  
//default value of nSplitter is 5 lcih [M6z  
this("","","",5);  /8.;  
} ;$nK ^  
m^`X|xK-  
b*,R9  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ros5]5=dP  
{ :yv!  x  
sSiteURL= sURL; JjM^\LwKkL  
sFilePath = sPath; ! $n^Ze2 !  
sFileName = sName; h~dM*yo;  
this.nSplitter = nSpiltter; ]TGJ|X  
-i 9/1.Z  
%e _WO,R  
} U9Y'eP.2  
u+{5c5_  
r,F'Jd5  
public String getSSiteURL() (33[N  
{ p/@z4TCNX  
return sSiteURL; {`-EX  
} qlSMg;"Ghw  
^y&l!,(A   
ZgN*m\l  
public void setSSiteURL(String value) `9@!"p f  
{ AX6e}-S1n  
sSiteURL = value; eK]GyY/Y  
} Z$2mVRS`c  
)M1.>?b  
K":- zS  
public String getSFilePath() XfB;^y=u8  
{ 2 !{P<   
return sFilePath; y#r=^r]l)  
} qD 2<-E&M/  
K?P.1H`  
%R(j|a9z  
public void setSFilePath(String value) | YvO$4=s  
{ Yh"R#  
sFilePath = value; S7-?&[oeJ  
} Dz.U&+*  
Rb#?c+&#  
5FzG_ w  
public String getSFileName() V$@@!q  
{ w W-GBY3  
return sFileName; T Li0*)}  
} GMksr%0Pj  
S# SA:>8s  
N+h|Ffnp  
public void setSFileName(String value) x%LWcT/  
{ .nT"f>S&'  
sFileName = value; a]75z)X R  
} t,+p!"MRY  
NH4EsV]  
J\#6U|a""u  
public int getNSplitter() l@## Ex9  
{ !SVW}Q=5#  
return nSplitter; l~!#<=.  
} ^fH]Rlx  
]kc]YO7i%R  
P%.9g  
public void setNSplitter(int nCount) V5R``T p  
{ D,]m7 yFT  
nSplitter = nCount; &AA u:  
} MiN68x9  
} Ro?yCy:L'  
76xgExOU?C  
;9d(GP}eE  
/* i9w xP i  
**Utility.java 7M5HIK6_  
*/ T7&itgEYG/  
package NetFox; <4^a (Zh  
2uV=kqnO  
:y 0'[LV  
public class Utility { iQ~cG[6  
DtyT8kr  
wMei`svY  
public Utility() Dr<%Lr  
{ 90M:0SH  
CfA F.H  
S =eP/  
} *9*6n\~aI  
WF_G GF{  
//线程睡眠 6$2)m;| XY  
public static void sleep(int nSecond) p}N'>+@=  
{ !j [U  
try{ 3K P6M=  
Thread.sleep(nSecond); $  5  
} .GLotc  
catch(Exception e) {P(IA2J'S  
{ zaR~fO  
e.printStackTrace (); BwrMRMq"  
} C'kd>LAGu  
} l{vi{9n)  
w ~Es,@  
//日志 "0n to+v  
public static void log(String sMsg) a!4'}gHR  
{ hNSV}~h  
System.err.println(sMsg); sLb[ZQ;j  
} H#G'q_uHH  
PJ9JRG7j  
^P(HX  
public static void log(int sMsg) {H"xC~.  
{ Aln\:1MU  
System.err.println(sMsg); T3Qa[>+\  
} B3e{'14  
} %q(n'^#Z.y  
LR'F/.Dx  
5=5~GX-kr  
/* MhHygZT[}  
**TestMethod.java xs+MvXTC  
*/ : !J!l u  
package NetFox; kQwBrb 4  
EVrOu""  
=@&]PYv  
public class TestMethod { o=4d2V%m  
+*~?JT  
3x.|g   
public TestMethod() V1;n5YL  
{ ///xx/weblogic60b2_win.exe a{,EX[~b  
try{ $nBzYRc"3  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M*{ EK  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]hN%~ ~$>  
SiteFileFetch fileFetch = new SiteFileFetch(bean); A1>R8Zuhy  
fileFetch.start(); !SKEL6~7  
} @R(6w{h9  
catch(Exception e){e.printStackTrace ();} zr2%|YF  
a*KB'u6&  
cPkN)+K  
} Z#nj[r!l}  
bsR&%C  
kT!FC0E{  
public static void main(String[] args) bY&s $Ry3"  
{ #*1\h=bzmW  
new TestMethod(); i{ eDV  
} ,z<\Z!+=  
} %)u5A !"  
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