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http断点续传简单实现(java)

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/* N>h]mX6  
**SiteFileFetch.java !G@V<'F  
*/ an #jZ[  
package NetFox; t/_\U =i$  
import java.io.*; :^C#-O  
import java.net.*; DB!uv[c  
t4*aVHT  
/<G yg7o0  
public class SiteFileFetch extends Thread { WIhIEU7/  
_q2`m  
3BuD/bs  
SiteInfoBean siteInfoBean = null; //文件信息Bean =2Pz$q*ub  
long[] nStartPos; //开始位置 MX%|hIOpr  
long[] nEndPos; //结束位置 }"!6Xm  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 i@sCMCu6  
long nFileLength; //文件长度 Z{j!s6Y@{  
boolean bFirst = true; //是否第一次取文件 Iht mD@H}  
boolean bStop = false; //停止标志 4"`=huQ  
File tmpFile; //文件下载的临时信息 GA}hp%  
DataOutputStream output; //输出到文件的输出流 kjQIagw  
})Ix .!p  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) C8O7i[uc  
public SiteFileFetch(SiteInfoBean bean) throws IOException "@F*$JGT y  
{ OD>u$tI9  
siteInfoBean = bean; BIwgl@t!>  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); lU >)n  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ci#Zvhtk r  
if(tmpFile.exists ()) i&? 78+:  
{ q>wa#1X)  
bFirst = false; AqTR.}H  
read_nPos(); `XFX`1  
} YLr%vnO*NS  
else >& 4I.nA  
{ _CYmG"mY  
nStartPos = new long[bean.getNSplitter()]; Y,p2eAss  
nEndPos = new long[bean.getNSplitter()]; exGhkt~  
} +sV#Z,  
4'7 v!I9  
#w[q.+A  
_Y:Ja0,  
} +Px<DX+  
LL6ON }  
)4VL m  
public void run() [U_Q 2<H  
{ 4IH0un  
//获得文件长度 8tG/VE[  
//分割文件 e\+~  
//实例FileSplitterFetch wt3Z?Pb  
//启动FileSplitterFetch线程 T/X?ZK(T  
//等待子线程返回 I3F6-gH  
try{ 6jQ&dN{=qB  
if(bFirst) Al;%u0]5  
{ Q)7L^  
nFileLength = getFileSize(); {g23[$X]N  
if(nFileLength == -1) I{Y {  
{ kM}ic(K  
System.err.println("File Length is not known!"); Z:r$;`K/  
} D:S6Mu  
else if(nFileLength == -2) j.G.Mx"  
{ >8.v.;`  
System.err.println("File is not access!"); ;8 /+wBnm  
} +)''l  
else  `i_L?C7  
{ h<!khWFS  
for(int i=0;i<nStartPos.length;i++) e2_r0I^C  
{ %$!R]B)  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 9Le/'ovq  
} v\r7.l:hf  
for(int i=0;i<nEndPos.length-1;i++) 8kn]_6:3i  
{ HCn ]#  
nEndPos = nStartPos[i+1]; `eA&C4oFOO  
} u:qD*zOq  
nEndPos[nEndPos.length-1] = nFileLength; ~L Bq5a  
} VAG+y/q  
} zN8&M<mTl  
^`B##9g~  
dcc%G7w  
//启动子线程 >(1_Dn\  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^~*[~  
for(int i=0;i<nStartPos.length;i++) +p%5/ smfs  
{ #xJGuYdv  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R)DNFc:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8 MACbLY  
nStartPos,nEndPos,i); WPh |~]by<  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 5;i!PuL  
fileSplitterFetch.start(); k(vEp ]  
} o )}<   
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !xx> lX5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); \p=W4W/  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", `!>dbR&1  
nEndPos = " + nFileLength); Jr*S2 z<*  
// fileSplitterFetch[nPos.length-1].start(); U{:(j5m  
Z2pN<S{5  
\w@_(4")Qb  
//等待子线程结束 Rs( CrB/M  
//int count = 0; H--*[3".  
//是否结束while循环 q4#f *]  
boolean breakWhile = false; Y|qixpP  
9OO_Hp#|9  
6pdl,5[x-  
while(!bStop) Lb3K};SIV  
{ 2 vJ[vsrFv  
write_nPos(); 0qV*d  
Utility.sleep(500); fG[3%e  
breakWhile = true; DJ2]NA$Q*  
*Yk8Mj^_h  
e 7)%=F/)  
for(int i=0;i<nStartPos.length;i++) g  cK"  
{ N@du.d:  
if(!fileSplitterFetch.bDownOver) 1p "EE~ v  
{ i2%m}S;D9  
breakWhile = false; ,B/p1^;.  
break; 4>wIF}\  
} lVp~oZC6[  
} h9OL%n 7m'  
if(breakWhile) 0)]C&;}_M  
break; SYW= L  
^*UfCoj9Z  
 W$VCST  
//count++; GO GXM4I  
//if(count>4) G]NtX4'4  
// siteStop(); >7Sl( UY-  
} 6+f>XL#w  
36A.h,~  
oTV8rG  
System.err.println("文件下载结束!"); 'Tan6 Qa  
} mEc;-b f  
catch(Exception e){e.printStackTrace ();} g KmRjK  
} `J7Lecgo  
f[I'j0H%  
pN f9  
//获得文件长度 ]ieA?:0Hi  
public long getFileSize() /KvPiQ%  
{ Y" +1,?yH  
int nFileLength = -1; sq (063l  
try{ V<7K!<g)b  
URL url = new URL(siteInfoBean.getSSiteURL()); eYX_V6c  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !DUg"o3G>  
httpConnection.setRequestProperty("User-Agent","NetFox"); %LZM5Z^  
G mUs U{  
w wRT$-!  
int responseCode=httpConnection.getResponseCode(); W;}u 2GH  
if(responseCode>=400) {$TB#=G  
{ xS-nO_t 'E  
processErrorCode(responseCode); l|tp0[  
return -2; //-2 represent access is error wj5s5dH  
} c:_i)":  
<7-,`   
LW 3J$Am  
String sHeader; pmD-]0  
w7?9e#> Z  
=v`&iL~m  
for(int i=1;;i++) MdboWE5i  
{ 6{r[Dq  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S^`9[$KH0  
//Utility.log(in.readLine()); xr3PO?:  
sHeader=httpConnection.getHeaderFieldKey(i); #2'&=?J1r  
if(sHeader!=null) ^V,/4u  
{ b0=AQ/:  
if(sHeader.equals("Content-Length")) !J(,M)p!  
{ *rKv`nva5  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); QM=436fq  
break; v%~ViOgL\  
} " /-v 9  
} tYNt>9L|  
else Nv]/L +i  
break; cYn}we}7  
} XlJux_LD:  
} E_uH' E  
catch(IOException e){e.printStackTrace ();} ^X'7>{7Io  
catch(Exception e){e.printStackTrace ();} 'n.9qxY;  
lc(iy:z@  
)g^Ewzy^X  
Utility.log(nFileLength); &_9e g  
R:m=HS_  
Y6;9j=[  
return nFileLength; ?o'arxCxZn  
} {#Cm> @')  
+Z(VWu6  
E004"E<E  
//保存下载信息(文件指针位置) @<JQn^M  
private void write_nPos() vrx3O  
{ e1}0f8%  
try{ n:)Y'52}  
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3H %WB|  
output.writeInt(nStartPos.length); &c ~)z\$  
for(int i=0;i<nStartPos.length;i++) <"%h1{V  
{ z{WqICnb  
// output.writeLong(nPos); ,IATJs$E  
output.writeLong(fileSplitterFetch.nStartPos); [kkcV5I-  
output.writeLong(fileSplitterFetch.nEndPos); ^P`'qfZ  
} ]>T/Gl1  
output.close(); qiJ{X{lI  
} r26Wysi~%  
catch(IOException e){e.printStackTrace ();} YWF<2l.  
catch(Exception e){e.printStackTrace ();} . Dxrc  
} R;2 -/MT-  
YHAg4 eb8  
nEr, jd~f  
//读取保存的下载信息(文件指针位置) 7s3<}  
private void read_nPos() K#m o+n5-;  
{ 6E4L4Vb  
try{ JwVv+9hh  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); th|Q NG  
int nCount = input.readInt(); aX:$Q }S  
nStartPos = new long[nCount]; 6* w;xf  
nEndPos = new long[nCount]; _ RT}Ee}Y  
for(int i=0;i<nStartPos.length;i++) [wYQP6Cyy  
{ mn` Ae=  
nStartPos = input.readLong(); HEN9D/O=  
nEndPos = input.readLong(); U %l{>*q  
} 8G<.5!f7`N  
input.close(); nJC}wh2d#  
} b7mP~]V  
catch(IOException e){e.printStackTrace ();} &T}e9 3]  
catch(Exception e){e.printStackTrace ();} }$U6lh/Ep  
} ]h@:Y]  
OSU=O  
Q)&Ztw<  
private void processErrorCode(int nErrorCode) mj~CCokF{?  
{ Y [S^&pF  
System.err.println("Error Code : " + nErrorCode); FFGTIT# {"  
} (^\i(cfu6Q  
'5\1uB PKW  
aR $P}]H  
//停止文件下载 +M:Q!'  
public void siteStop() |05LHwb>  
{ @DR&e^Zz  
bStop = true; %Kp}Wo6  
for(int i=0;i<nStartPos.length;i++) (FHh,y~v  
fileSplitterFetch.splitterStop(); )cXc"aj@s  
z>~3*a9&  
$i Tgv?.Q  
} s<]l[Y>  
} "'(4l 2.  
//负责部分文件的抓取 L Jx g  
**FileSplitterFetch.java ,55`s#;  
*/ !2}Q9a  
package NetFox; 9 |Y?#oZ1  
Mt>DAk  
o}z}79Z  
import java.io.*; U>XGJQ<NS  
import java.net.*; $4pW#4/4  
8Qh/=Ir  
_i#Z'4?2E  
public class FileSplitterFetch extends Thread { 50A_+f.7%  
0Jr< >7Q1  
X)+N>8o?N  
String sURL; //File URL ^xrR3m*d  
long nStartPos; //File Snippet Start Position i`;I"oY4  
long nEndPos; //File Snippet End Position duCm+4,.  
int nThreadID; //Thread's ID l?~h_8&fT  
boolean bDownOver = false; //Downing is over 6G],t)<A'-  
boolean bStop = false; //Stop identical :nt%z0_  
FileAccessI fileAccessI = null; //File Access interface 3-D!ZS&  
=%p{ " <  
Ycwb1e#  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o hCPNm  
{ P.0-(  
this.sURL = sURL; `Ii>w b  
this.nStartPos = nStart; .wywO|  
this.nEndPos = nEnd; >xN^#$ng}  
nThreadID = id; gUcE,L  
fileAccessI = new FileAccessI(sName,nStartPos);//定位  CgWj9 [  
} >KJ]\`2>)c  
gMbvHlT  
Z[VKB3Pb8  
public void run() g@L4G?hLn  
{ (Lp-3Xx  
while(nStartPos < nEndPos && !bStop) t/CNxfY  
{ 2_Qzc&"[ 4  
%oo&M;  
n_Z8%|h  
try{ x$E l7=.  
URL url = new URL(sURL); pFuQ!7Uk  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $O#h4L_  
httpConnection.setRequestProperty("User-Agent","NetFox"); kH'Cx^=c6h  
String sProperty = "bytes="+nStartPos+"-"; NKRXY~zHh  
httpConnection.setRequestProperty("RANGE",sProperty); ~Y(M>u.+!  
Utility.log(sProperty); @tA.^k0`  
= N#WwNC  
$W2AiE[Wm  
InputStream input = httpConnection.getInputStream(); C+Z"0\{o  
//logResponseHead(httpConnection); @fw U%S[v  
, F[mh  
SO%5ts  
byte[] b = new byte[1024]; 19EU[eb  
int nRead; 2-~oNJqX  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fjb2-K  
{ W[jxfZD9v  
nStartPos += fileAccessI.write(b,0,nRead); 2:abe  
//if(nThreadID == 1) R[(,wY_1  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H_Yy.yi  
} =cQw R:):  
ATU@5,9  
<i5^izg  
Utility.log("Thread " + nThreadID + " is over!"); ]k Pco4  
bDownOver = true; Dj|S  
//nPos = fileAccessI.write (b,0,nRead); I4hr5M3  
} (R, eWWF8~  
catch(Exception e){e.printStackTrace ();} ?OSd8E+itM  
} ]1K &U5p  
} /H)g<YA  
iw{n|&Y#`  
cA*%K[9  
//打印回应的头信息 {MS&t09Wh  
public void logResponseHead(HttpURLConnection con) P+/L, u  
{ gSC@uf  
for(int i=1;;i++) Pzqgg43Xf  
{ Z`W.(gua  
String header=con.getHeaderFieldKey(i); ;KhYh S(q  
if(header!=null) -nW{$&5AF  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 75F&s,4+  
Utility.log(header+" : "+con.getHeaderField(header)); 3"".kf,O5e  
else H Ow hl  
break; _eF*8 /z  
} ,%C$~+xjM  
} (mEZ4yM  
IkvH8E  
(Cq-8**dY  
public void splitterStop() zt8ZJlNK  
{ C" sa.#}  
bStop = true; m} V,+E  
} IH0Uq_  
0C7"*H0 R  
bhI8b/  
} S$#Awen"@  
n5b N/  
H\S,^)drJ?  
/* 29GiNy+ob  
**FileAccess.java m4iR '~L}  
*//文件访问(定位,写) ]mc,FlhU@  
package NetFox; B5cTzY.h-  
import java.io.*; , R)[$n  
OJ 2M_q)e  
6?~pWZ&k_  
public class FileAccessI implements Serializable{ 1~*_H_Q't  
* n[6H  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =:b/z1-v  
RandomAccessFile oSavedFile; #: F)A_Y  
long nPos; 3lJK[V{'#'  
A;g[G>J  
pSAXp# g  
public FileAccessI() throws IOException >8VJ!Kg4  
{ Ua:EI!`  
this("",0); t!~mbx+  
}  LKm5U6  
BP7_o63/G  
 A=,m  
public FileAccessI(String sName,long nPos) throws IOException YP6+o#==  
{ )KNFS,5  
oSavedFile = new RandomAccessFile(sName,"rw"); R6!3Y/Q@  
this.nPos = nPos; ; R67a V,  
oSavedFile.seek(nPos); 0QPipuP  
} =m40{  
wjl? @K  
Kb}N!<Z*  
public synchronized int write(byte[] b,int nStart,int nLen) 4b#YpK$7U  
{ y0Tb/&xN  
int n = -1; LC}]6  
try{ (]pQ.3  
oSavedFile.write(b,nStart,nLen); O-7 \qz  
n = nLen; \h yTcFb  
} koUH>J:  
catch(IOException e) t^YDCcvoQ  
{ b/ynCf8X  
e.printStackTrace (); OS!47Z /q  
} )y K!EK\  
Wc)^@f[~<  
w"D"9 G  
return n; n;MoMGnPh,  
} a5)+5  
2q#$?qs_b  
Ft]sTA+C  
} %jkd}D  
t;*'p  
`R^)< v*  
/* T}zi P  
**SiteInfoBean.java [ -%oO  
*/ w#o<qrpHf  
package NetFox; 0 cQf_o  
:9)>!+|'  
B1GSZUd^?0  
public class SiteInfoBean { )~J/,\  
&K7g8x"x.  
Lt*H|9  
private String sSiteURL; //Site's URL Ah"Rx A  
private String sFilePath; //Saved File's Path !ine|NM  
private String sFileName; //Saved File's Name )S`A+M K]  
private int nSplitter; //Count of Splited Downloading File 9/'j<v6M  
Mn=_lhW K  
JRG7<s $  
public SiteInfoBean() _[<I&^%  
{//nSplitter的缺省值为5 86I".R$d  
//default value of nSplitter is 5 > 4^U=T#  
this("","","",5); xv)7-jlx  
} !is8`8F8  
ZpwB"%e$  
G1D(-X4ALZ  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Um|:AT}`^  
{ { u;ntDr  
sSiteURL= sURL; 3(CUC  
sFilePath = sPath; =e4,)Wd9&  
sFileName = sName; ve>8vw2  
this.nSplitter = nSpiltter; Ar\`OhR  
#3qkG)  
{u!,TDt*  
} g'IS8@  
* "E]^wCn  
is6JS^Q  
public String getSSiteURL() .Wr7?'D1M  
{ yeW|Ux:  
return sSiteURL; "c}b qoN  
} vzVl2  
6h5*b8LxA  
oc15!M3$  
public void setSSiteURL(String value) D3jP hPy.  
{ UH)A n:9  
sSiteURL = value; Z(V 4"x7F  
} 10a=[\ Q  
F6fm{  
F'Wef11Yz  
public String getSFilePath() {}.c.W+  
{ Z{e5 OJ  
return sFilePath; 'SuYNA)  
} 8]0R[kjD  
,C CIg9Pt  
M#:Mwa$  
public void setSFilePath(String value) 3fGy  
{ ?.4u'Dkn=  
sFilePath = value; N!P* B $d  
} ^+}<Q#y-  
8sL7p4  
WjA)0HL(  
public String getSFileName() b]J_R"}  
{ (5atU |8r  
return sFileName; NE/3aU  
} k1]?d7g$w  
h'N,oDB)  
]o_ Ps|  
public void setSFileName(String value) ]A_)&`"Cb  
{ z`/v}'d[X  
sFileName = value; lfCoL@$6D  
} ;KnnAZJ  
Zaq:l[%  
@ws3X\`<C  
public int getNSplitter() Haturg  
{ yvVs9"|0  
return nSplitter; 9<xe%V=ki  
} u[cbRn,W  
a1s=t_wT  
ne;,TJ\  
public void setNSplitter(int nCount) &oAuh?kTq  
{ i8 dv|oa  
nSplitter = nCount; 8 2_3|T  
} PI }A')Nq.  
} Ha;^U/0|  
4$.4,4+  
6W~F nJI  
/* FzW(An&x2  
**Utility.java aLP 2p]  
*/ Ii;~ xc  
package NetFox; ]T+{]t  
Mj[ v _&N  
tdEu4)6  
public class Utility { '?q|7[SU  
Yj;$hV8j(  
cz.-cuD[iD  
public Utility() @1rF9< 4g  
{ R_(A&,  
PF4Cs3m/  
Ff.gRx  
} .O~)zM x  
(3W<yAM+  
//线程睡眠 [ UQzCqV  
public static void sleep(int nSecond) *-g S u  
{ 8_W<BXW  
try{ {L3lQ8Z  
Thread.sleep(nSecond); jH \@Oc;7  
} hYF<Wn3L  
catch(Exception e) '|Cs!Zl  
{ 0gxbo  
e.printStackTrace (); ?e yo2:-$  
} ij%\ld9kd  
} MB:E/  
+|\dVe.  
//日志 1)M3*h3  
public static void log(String sMsg) L{osh0  
{ sexnO^s  
System.err.println(sMsg); Av7bp[OD  
} 3_ObCsJ#,  
lO)p  
t[7YMk  
public static void log(int sMsg) O[Nc$dc  
{ wB "&K;t  
System.err.println(sMsg); 4km=KOx[  
} |VTm5.23  
} nB"q  
"o% N`Xlx  
%Wn/)#T|  
/* ~E#>2Mh  
**TestMethod.java 9fyk7~ V  
*/ |Q.t]TR'P  
package NetFox; w#]%I+  
mG\,T3/*  
hyFq>XFo  
public class TestMethod { TRG"fVR  
GIt; Y  
y~''r%]   
public TestMethod() NSj}?hz  
{ ///xx/weblogic60b2_win.exe g,mcxXO  
try{ wbVM'E/&  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); [sbC6(z  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :,6dW?mun6  
SiteFileFetch fileFetch = new SiteFileFetch(bean); bvs0y7M='  
fileFetch.start(); USJ4qv+-  
} hAKyT~[n0  
catch(Exception e){e.printStackTrace ();} ,~%Qu~\  
-7hU1j~I  
<HI5xB_  
} hP,SvN#!2  
[K x_%Le  
0}-&v+  
public static void main(String[] args) %TvunV7NQS  
{ @D Qg1|m  
new TestMethod(); hekAics6S  
} ngn%"xYX  
} K-(,,wS  
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