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http断点续传简单实现(java)

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/* xv(xweV+d  
**SiteFileFetch.java >8F{lbEe  
*/ s)`1Rf  
package NetFox; g4.'T51  
import java.io.*; {Q#Fen ;y|  
import java.net.*; iuH8g  
qxg7cj2  
7~%  
public class SiteFileFetch extends Thread { F$sF 'cw  
I;kUG_c(4  
P?3YHa^up  
SiteInfoBean siteInfoBean = null; //文件信息Bean V5(tf'  
long[] nStartPos; //开始位置 5~kW-x  
long[] nEndPos; //结束位置 cx1WGbZ  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 D x >1y  
long nFileLength; //文件长度  q~:'R  
boolean bFirst = true; //是否第一次取文件 ECE{xoc  
boolean bStop = false; //停止标志 mPw56>  
File tmpFile; //文件下载的临时信息 6qHvq A,  
DataOutputStream output; //输出到文件的输出流 "0!eb3n  
|({UV-`  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) b;~EJ  
public SiteFileFetch(SiteInfoBean bean) throws IOException sg9x?Bx9  
{ 21)-:rS  
siteInfoBean = bean; h Vt+%tmNy  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); .SKNIct M  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ; ei<Q =[  
if(tmpFile.exists ()) !lt\2Ae  
{ `|ck5DZT5L  
bFirst = false; 6S+K*/w  
read_nPos(); oE|u;o  
} X{9JSq  
else J*6n6  
{ 2gC&R1 H  
nStartPos = new long[bean.getNSplitter()]; 0x9F*i_  
nEndPos = new long[bean.getNSplitter()]; B1i!te}*  
} k1LtqV  
4 L~;>]7  
M#8Ao4 T  
X~Rk ,d3  
} !=q:> }g  
i"\AyKiJ  
P/1UCITq}  
public void run() |<+|Du1  
{ L]L~TA<D9i  
//获得文件长度 @e?[oojrM  
//分割文件 Oa_o"p<Lr  
//实例FileSplitterFetch -<}>YtB Q  
//启动FileSplitterFetch线程 G+QNg .pH  
//等待子线程返回 CrwcYzrRWl  
try{ ]`i@~Z h\  
if(bFirst) 2'UFHiK  
{ n\8[G [M  
nFileLength = getFileSize(); @qr3v>3X<  
if(nFileLength == -1) E't G5,/m  
{  _.J[w6  
System.err.println("File Length is not known!"); ,j(p}t  
} luxKgcU  
else if(nFileLength == -2) &L~31Ayj&  
{ $=QGua V  
System.err.println("File is not access!"); lj SR?:\  
} uI:3$  
else |@Idf`N$  
{ #3:'lGBIK  
for(int i=0;i<nStartPos.length;i++) dc@wf;o  
{ s2' :&5(  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 4f@\f7 \  
} L8-[:1  
for(int i=0;i<nEndPos.length-1;i++) :+dWJNY:  
{ HV.|Eh_7  
nEndPos = nStartPos[i+1];  ~bWWu`h  
} Z$m2rZ#  
nEndPos[nEndPos.length-1] = nFileLength; \q d)l  
} pil*/&pB  
} h C`p<jp/  
B| 0s4E  
j C1^>D  
//启动子线程 4kY{X%9  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e#eO`bT  
for(int i=0;i<nStartPos.length;i++) d&R\7)0  
{  rgvc5p  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t;f p<z7N.  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?[4khQt  
nStartPos,nEndPos,i); s:Ql](/B#  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); r1[T:B'  
fileSplitterFetch.start(); n)?F 9Wap  
} o? xR[N-J  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2T2#HP  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); WZ V*J&  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", .=w`T #L  
nEndPos = " + nFileLength); Ckl]fy@D}  
// fileSplitterFetch[nPos.length-1].start(); JU2' ~chh  
wqoN@d  
I:>d@e/;  
//等待子线程结束 ]O(HZD%  
//int count = 0; S?z j&X Y3  
//是否结束while循环 VA r?teY  
boolean breakWhile = false; uKAHJ$%  
Kmf-l*7}  
WxP4{T* <  
while(!bStop) ="TOa"Zk  
{ jw%FZ  
write_nPos(); #FDu 4xi  
Utility.sleep(500); P9cI{RI  
breakWhile = true; *CD=cmdD*  
h|>n3-k|p  
0c;"bA0>Sx  
for(int i=0;i<nStartPos.length;i++) o!dkS/u-m  
{ (L  
if(!fileSplitterFetch.bDownOver) DmpJzH j|  
{ ,`2xfVa-  
breakWhile = false; g$+O<a@n  
break; ;8xn"G0}a  
} `DY4d$!4  
} OZ]3OL,  
if(breakWhile) F^v{Jqc  
break; >v4~:n2D  
W)P_t"'@L  
Vm8_ !$F  
//count++; <YNPhu~5  
//if(count>4) }Ml z\'{  
// siteStop();  ]mU*Y:<  
} LZbHK.G=  
"'dC>7*<  
E0x$;CG!  
System.err.println("文件下载结束!"); ]CJ>iS!V  
} (%IstR|u:  
catch(Exception e){e.printStackTrace ();} H.S|njn:r  
} ]vyF&`phb  
'eXw`kw(  
u= i^F|  
//获得文件长度 b,V=B{(~  
public long getFileSize() lxJ.h&"P  
{ wDTV /"Y  
int nFileLength = -1; (I 0t*Se  
try{ 2F(\}%UT~  
URL url = new URL(siteInfoBean.getSSiteURL()); _)H+..=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cmLu T/oV  
httpConnection.setRequestProperty("User-Agent","NetFox"); _4#psxl[M  
lMf5F8  
, &f20o  
int responseCode=httpConnection.getResponseCode(); )8>f  
if(responseCode>=400) vK>^#b3  
{ ] :#IZ0#  
processErrorCode(responseCode); Mj;'vm7#'  
return -2; //-2 represent access is error G7{:d  
} H~K2`Cr)4  
<NsT[r~C  
l;FgX+)  
String sHeader; R20GjWy=  
~ a&j4E  
bg. KkJMrR  
for(int i=1;;i++) QI{Y@xQ  
{ ! \Kh\  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J4^cd  
//Utility.log(in.readLine()); !@ '2  
sHeader=httpConnection.getHeaderFieldKey(i); LBi>D`]  
if(sHeader!=null) JKbB,  
{ ^0~1/ PhOw  
if(sHeader.equals("Content-Length")) ZDD|MH  
{ fYPU'"hzG  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v0J1%{/xs  
break; _$lQK{@rY  
} by[(9+/z$  
} P &._ -[  
else wd0ACF  
break; /;ITnG  
} "Y0[rSz,UW  
} |0%UM}  
catch(IOException e){e.printStackTrace ();} Jxp'.oo[  
catch(Exception e){e.printStackTrace ();} nuA!Jln_  
J#WPXE+Ds  
,i.P= o  
Utility.log(nFileLength); _kLoDju%  
wfzb:Aig`  
]<= t  
return nFileLength; sVnu Sm  
} 0g)mf6}o  
#XPU$=  
#| Po&yu4R  
//保存下载信息(文件指针位置) e.H"!X!0#H  
private void write_nPos() X y<KvFy  
{ R>q'Ymu~  
try{ J[AgOUc  
output = new DataOutputStream(new FileOutputStream(tmpFile)); l<6/ADuS  
output.writeInt(nStartPos.length); Y{@[)M{<  
for(int i=0;i<nStartPos.length;i++) %syBm  
{ |Ay#0uQ5Y  
// output.writeLong(nPos); }y/t~f+  
output.writeLong(fileSplitterFetch.nStartPos); =@MKU  
output.writeLong(fileSplitterFetch.nEndPos); ? xs0J  
} !*-cf$  
output.close(); :gt wvM7/B  
} R[t[M}q  
catch(IOException e){e.printStackTrace ();} ,#haai(  
catch(Exception e){e.printStackTrace ();} V [>5  
} 1vb0G ;a;|  
>o7k%T|l$  
3!x)LUWfWY  
//读取保存的下载信息(文件指针位置) )9->]U@  
private void read_nPos() &YMj\KmlSg  
{ (*]Y<ve  
try{ hn .fX:}  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); n]!H,Q1,T  
int nCount = input.readInt(); ~3 (>_r  
nStartPos = new long[nCount]; t|lv6-Hy9  
nEndPos = new long[nCount]; 5. i;IOx  
for(int i=0;i<nStartPos.length;i++) 70~]J8T+u  
{ N~(}?'y9S  
nStartPos = input.readLong(); g9JtWgu  
nEndPos = input.readLong(); tWuQKN`_  
} qE[}Cf]X  
input.close(); $Izk]o;X~  
} _De;SB %V  
catch(IOException e){e.printStackTrace ();} }Of^Y@{q.  
catch(Exception e){e.printStackTrace ();} = '[@UVH(Z  
} -6\9B>qa  
k,,}N 9  
^ z;pP  
private void processErrorCode(int nErrorCode) .v{ty  
{ "mA/:8`Q  
System.err.println("Error Code : " + nErrorCode); _QY "#  
} l ki(_ @3  
8:MYeE5  
cW\7yZh  
//停止文件下载 "+AD+D  
public void siteStop() f?QD##~;  
{ !Fi)-o  
bStop = true; {Bx\Z0+'&  
for(int i=0;i<nStartPos.length;i++) hSmM OS{  
fileSplitterFetch.splitterStop(); gqG"t@Y+  
>e%Po,Fg$  
<V{BRRx  
} Aj_}B.  
} aUV>O`|_  
//负责部分文件的抓取 ux=@"!PJ  
**FileSplitterFetch.java S{ !hpq~o  
*/ :gXj( $  
package NetFox; R.@GLx_zpQ  
hS  Sq=(S  
9z#IdY$a  
import java.io.*;  NNX/2  
import java.net.*; _>.%X45xi  
cQjJ9o7  
bc-"If Z&  
public class FileSplitterFetch extends Thread { _" n4SXhq  
Qk= w ,`  
4p]Y`];U  
String sURL; //File URL %{Gqhb=u\  
long nStartPos; //File Snippet Start Position O1A*-G:X  
long nEndPos; //File Snippet End Position i~4Kek6,I  
int nThreadID; //Thread's ID S1."2AxO  
boolean bDownOver = false; //Downing is over !?96P|G  
boolean bStop = false; //Stop identical @47TDCr  
FileAccessI fileAccessI = null; //File Access interface 7">.{ @S  
x =k$^V~  
Dqki}k~{  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QnqX/vnR  
{ ,=FYf|Z  
this.sURL = sURL; Z6I!4K  
this.nStartPos = nStart; H={,zZ11{  
this.nEndPos = nEnd; -{?Rq'H  
nThreadID = id; _v\QuI6  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 +x1sV*S  
} I('l )^m%  
]TQjk{X<  
pw,.*N3P  
public void run() (/^&3xs9  
{ <]<50  
while(nStartPos < nEndPos && !bStop) m~v Ie c  
{  EpiagCS  
|R4](  
x/ez=yd*l  
try{ *\> &  
URL url = new URL(sURL); +{s^"M2`  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (L\tp> E-  
httpConnection.setRequestProperty("User-Agent","NetFox"); D4G{= Y}G  
String sProperty = "bytes="+nStartPos+"-"; W\Gg!XsLk  
httpConnection.setRequestProperty("RANGE",sProperty); -`( :L[  
Utility.log(sProperty); nv={.H  
Rj8l]m6U9  
uzS57 O%  
InputStream input = httpConnection.getInputStream(); *m;L.r`5[  
//logResponseHead(httpConnection); eK`tFs,u  
g$+3IVq&  
Q{%ow:;s*  
byte[] b = new byte[1024]; lm+wjhkN  
int nRead; `bi5#xR  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) GRNH!:e  
{ @{bf]Oc  
nStartPos += fileAccessI.write(b,0,nRead); N7[~Y2i  
//if(nThreadID == 1) &CS=*)>$  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \"Np'$4eu  
} *Hs5MXNu  
Lczcz"t  
:r\<DVj  
Utility.log("Thread " + nThreadID + " is over!"); hAY_dM  
bDownOver = true; [=iq4F'7  
//nPos = fileAccessI.write (b,0,nRead); f"[C3o2P  
} (Fu9lW}n  
catch(Exception e){e.printStackTrace ();} d"V^^I)yx&  
} _|F h^hq  
} u+]zi"k^s  
]$7|1-&Y  
%T&kK2d;  
//打印回应的头信息 MT3UJ6~P  
public void logResponseHead(HttpURLConnection con) rC'97`!K  
{ g}f@8;TY  
for(int i=1;;i++) g ,.iM8  
{ wBr0s *1I  
String header=con.getHeaderFieldKey(i); Z$q}y 79^  
if(header!=null) Ay{4R  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]WS 7l@  
Utility.log(header+" : "+con.getHeaderField(header)); #PiW\Tq  
else 6pH.sX$!_  
break; 2 nf{2edC  
} Y,+$vj:y8  
} )!0>2,R1  
U+\\#5$  
uG/Zpi  
public void splitterStop() S2`p&\Ifn  
{ GhX>YzD7  
bStop = true; oRCj]9I$  
} XX+4X*(o  
^mH^cP?/  
G-Y8<mEh  
} Baq&>]  
s01n[jQ  
x]F:~(P  
/* M]oaWQu  
**FileAccess.java V ] Z{0  
*//文件访问(定位,写) 1%>/%eyn5  
package NetFox; 1"i/*}M  
import java.io.*; . 8k9yk  
-cMqq$  
q>,i `*  
public class FileAccessI implements Serializable{ i7iL[+f]Q  
9Y0w SOSW  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <_h  
RandomAccessFile oSavedFile; 9OX&;O+5  
long nPos; ^W;\faG  
?v6xa Vg:  
orJN#0v4  
public FileAccessI() throws IOException h/5.>[VwDh  
{ PKmr5FB  
this("",0); oPl^tzO  
} '};pu;GA7  
h(ZZ7(ue  
?8pRRzV$  
public FileAccessI(String sName,long nPos) throws IOException m#ID%[hg$  
{ usU5q>1  
oSavedFile = new RandomAccessFile(sName,"rw"); | X! d*4  
this.nPos = nPos; nzU^G)  
oSavedFile.seek(nPos); "OkJPu2!W  
} Nv w'[?m  
!ouJ3Jn   
sZ_+6+ :  
public synchronized int write(byte[] b,int nStart,int nLen) Ubv<3syR'  
{ 54v}iG  
int n = -1; y$'(/iyz  
try{ ApR>b%  
oSavedFile.write(b,nStart,nLen); *{ 6{ZKM  
n = nLen; xO{yr[x"L  
} 5*C#~gd& F  
catch(IOException e) (*F/^4p!$  
{ ("?V|  
e.printStackTrace (); > <^ ,  
} O(#DaFJv  
icH\(   
^i:%0"[*^i  
return n; qi!+ Ceo}  
} s9X?tWuL  
WTbq)D(&[_  
E&9BeU a#  
} g{RVxGE7  
VBo=*gn,$  
C8ek{o)%W  
/* Dg W*Br8<  
**SiteInfoBean.java Y'H|Tk^`  
*/ P9c!   
package NetFox; br`cxgZ0"  
?NWc3 .  
-Q9} gaH_  
public class SiteInfoBean { d0YDNP%,_  
muc6gwBp  
lk;4l Z  
private String sSiteURL; //Site's URL m7!M stu  
private String sFilePath; //Saved File's Path Qq+$ea?>  
private String sFileName; //Saved File's Name Yv>kToa\^  
private int nSplitter; //Count of Splited Downloading File OO#_ 0qK  
y\k#83aU|  
opqY@>Vh&  
public SiteInfoBean() \SKobO?qI  
{//nSplitter的缺省值为5 @L0xU??"|  
//default value of nSplitter is 5 vY)5<z&  
this("","","",5); u0p[ltJ,  
} Ce_k&[AJF  
qjDt6B^RO  
-?nr q <3  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O/ybqU\7  
{ owQSy9Az  
sSiteURL= sURL; }JI@f14  
sFilePath = sPath; [0MNq]gxf  
sFileName = sName; ?sD4S   
this.nSplitter = nSpiltter; (P'{A>aHl0  
bY&!d.  
8n??/VDRl  
} z* k(` '  
h>k[  
< #FxI  
public String getSSiteURL() Nux  
{ 4]G J+a  
return sSiteURL; FJQ=611@  
} Uhs/F:E[A  
4Dy|YH$>S  
*\gYs{,  
public void setSSiteURL(String value) +cWo^d.  
{ 18nT Iz_  
sSiteURL = value; @k+ K_gR  
} O#Ma Z.=  
N1iP!m9Q  
6U9F vPJ  
public String getSFilePath() 1Be/(pSc  
{ m941 Y  
return sFilePath; vB<9M-sa0  
} {:] u 6l  
\Vb|bw'e(  
q{Ao j  
public void setSFilePath(String value) P"[\p|[U  
{ owviIZFe  
sFilePath = value; &ea6YQ  
} Dr K@y8  
n{$! ]^>  
A3^_'K  
public String getSFileName() ,J(shc_F  
{ Y6G`p  
return sFileName; 3!M|Sf<s  
} 'C7$,H'  
eHb@qKnf  
twMDEw#VL  
public void setSFileName(String value) u+ b `aB  
{ Z\r?>2  
sFileName = value; O\F$~YQ  
} go9tvK  
Yz)+UF,  
4OeH}@a  
public int getNSplitter() v` h n9O  
{ [>D5(O  
return nSplitter; |"g+p)A  
} R0~w F>  
!LM9  
}2h!  
public void setNSplitter(int nCount) ~^bf1W[  
{ BdrYc^?JL]  
nSplitter = nCount; (<2!^v0.M  
} ZiW&*nN?M  
} i^@hn>s$  
|@5G\N-  
`*WzHDv5p  
/* ^P|Zze zwU  
**Utility.java } _=h]|6t  
*/ NY?pvb  
package NetFox;  oP~%7Jt  
\NZ@>on  
$MqEM~^=  
public class Utility { 6<fcG  
\1sWmN6  
n"w>Y)C(X)  
public Utility() 0YZ66VN!  
{ :{,k F  
cs9"0&JX  
ioBYxbY`  
} ^+w1:C5  
v:"Y  
//线程睡眠 l} @C'Np  
public static void sleep(int nSecond) 3aw-fuuIb  
{ 9^7z"*@#  
try{ 4k!>JQor  
Thread.sleep(nSecond); |?v .5|1  
} T 9FGuit9  
catch(Exception e) 2y IDyo  
{ [>LO'}%  
e.printStackTrace (); &r+!rL Kp  
} *4/KK  
} xFcW%m>9C  
):\+%v^  
//日志 5?A<('2  
public static void log(String sMsg) `(r0+Qx  
{ #+H3b!8=  
System.err.println(sMsg); d*x&Uh[K  
} .qLX jU  
d ATAH}r&  
[HhaBy9  
public static void log(int sMsg) m2HO .ljc  
{ >>c%I c  
System.err.println(sMsg); !yvw5As%  
} @~&|BvK% \  
} 1:RK~_E  
tr58J% Mu  
m=TZfa^r  
/* Wo  Z@  
**TestMethod.java 5S[:;o  
*/ x \I uM  
package NetFox; k*OHI/uiow  
IOa@dUh7a,  
Wj8WT)cB  
public class TestMethod { ^B8 [B&K  
v%kl*K`*  
}zIWagC6  
public TestMethod() )Y`ybADd3  
{ ///xx/weblogic60b2_win.exe /]?e^akA  
try{ i|0!yID0@  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ;Fd1:"1pP  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /8 y v8  
SiteFileFetch fileFetch = new SiteFileFetch(bean); *TrpW?]Y&  
fileFetch.start(); ~R\ $Z  
} MAp#1+k  
catch(Exception e){e.printStackTrace ();} ..x 2  
P'<j<h6  
J\FLIw4  
} oBs5xH7@-  
G^Y^)pc]   
)LsUO#%DO  
public static void main(String[] args) %!DTq`F  
{ .@\(ay  
new TestMethod(); ] f5vk  
} K+d{R=s^  
} Xy}>O*  
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