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http断点续传简单实现(java)

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/* (m04Z2#  
**SiteFileFetch.java  N%r}0  
*/ D<++6HN&#  
package NetFox; Mh+'f 93  
import java.io.*; >j`*-(`2fa  
import java.net.*; 0^ E!P>  
:WA o{|&  
{tR=D_5  
public class SiteFileFetch extends Thread { "mPa >`?  
Go`omh b  
o4~ft!>  
SiteInfoBean siteInfoBean = null; //文件信息Bean oSa FmP  
long[] nStartPos; //开始位置 34;c00  
long[] nEndPos; //结束位置 Ac7`nvI=  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 >D:S)"  
long nFileLength; //文件长度 6{7O  
boolean bFirst = true; //是否第一次取文件 XIjSwR kYJ  
boolean bStop = false; //停止标志 3:Z(tM&-O  
File tmpFile; //文件下载的临时信息 m]"YR_  
DataOutputStream output; //输出到文件的输出流 @bqCs^U35  
?sS'T7r v  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) -S,dG|  
public SiteFileFetch(SiteInfoBean bean) throws IOException YSa:"A  
{ hq,;H40%/  
siteInfoBean = bean; '|XP}V0I  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); X2@o"xU  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); $}KYpSV  
if(tmpFile.exists ()) @{CpC  
{ ^ _+ks/  
bFirst = false; U1q$B32  
read_nPos(); `=KrV#/758  
} zi-+@9T  
else 0a'@J~v!  
{ ~!&[;EM<bm  
nStartPos = new long[bean.getNSplitter()]; B:mlBSH  
nEndPos = new long[bean.getNSplitter()]; .9^;? Ts  
} 'h= >ej*  
q!ZmF1sU  
@nc!(P7_  
\ 3LD^[qi  
} "5y^s!/  
FBY~Z$o0.  
#[[p/nAy}A  
public void run() NXmj<azED  
{ $Ilr.6';  
//获得文件长度 =u'/\nxCF  
//分割文件 /GeS(xzQ  
//实例FileSplitterFetch ZDDwh&h  
//启动FileSplitterFetch线程 ,@!d%rL:4]  
//等待子线程返回 WX=+\`NyJ(  
try{ P)\f\yb  
if(bFirst) 4Dd9cG,lN  
{ RsOK5XnQn  
nFileLength = getFileSize(); " LxJPt\  
if(nFileLength == -1) H~~(v52wD  
{ yv:NH|,/y  
System.err.println("File Length is not known!"); >u/yp[Ky  
} (w^&NU'e  
else if(nFileLength == -2) ;< ][upn  
{ dY|jV}%T  
System.err.println("File is not access!"); hqds T  
} /Z@.;M  
else <Q kfvK]Q  
{ |n|2)hC  
for(int i=0;i<nStartPos.length;i++) }>1E,3A:%G  
{ eS.]@ E-T  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); Qdn:4yk  
} -qEr-[z  
for(int i=0;i<nEndPos.length-1;i++) W ,U'hk%  
{ nx +& {hn(  
nEndPos = nStartPos[i+1]; W1!eY,1}  
} 6,h<0j{  
nEndPos[nEndPos.length-1] = nFileLength; jF5JpyOc  
} y@Or2bO#  
} 'q-h kN  
tQ|I$5jNJ  
Y~:7l5C  
//启动子线程 kL3=7t^ 1  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nSC>x:jY5/  
for(int i=0;i<nStartPos.length;i++) X@G`AD'.M  
{ n$?oZ *;  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }rQ*!2Y?  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G`P+J  
nStartPos,nEndPos,i); ;8v5 qz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ( 0h]<7  
fileSplitterFetch.start(); i~9)Hz;!  
} Cn<kl^!Q-  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |S8pq4eKJ_  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); C,]Ec2  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GGuLxc?(  
nEndPos = " + nFileLength); 3TtW2h>M  
// fileSplitterFetch[nPos.length-1].start(); aF=VJ+5  
:W&\})  
{h=Ai[|l4Q  
//等待子线程结束 ?7+ 2i\L  
//int count = 0; [~o3S$C&7  
//是否结束while循环 -+=8&Wa  
boolean breakWhile = false; <>Im$N ai  
gn%"dfm  
: L>d]Hn  
while(!bStop) z W _'sC  
{ YH>n{o;- ?  
write_nPos(); ;@ e |}Gk  
Utility.sleep(500); :+=*  
breakWhile = true; 3IkG*enI  
!:8!\gE ^P  
;4bu=<%  
for(int i=0;i<nStartPos.length;i++) 8dH|s#.4um  
{ N#:"X;  
if(!fileSplitterFetch.bDownOver) h CiblM  
{ \2`U$3Q  
breakWhile = false; u& Fm}/x  
break; l rzW H0Q  
} 3{l"E(qqZ  
} 0{yx*}.  
if(breakWhile) iI1t P  
break; Ame%:K!t  
_6' g]4  
b+hY^$//  
//count++; D4|_?O3 |m  
//if(count>4) WKf~K4BL>  
// siteStop(); Q'VS]n  
} 8\9EDgT  
7,zARWB!?  
4Rn i7qH  
System.err.println("文件下载结束!"); }NXESZYoi  
} vn<S"  
catch(Exception e){e.printStackTrace ();} cjXwOk1:s  
} y ^\8x^Eg  
;k8}D*?8  
}0( Na  
//获得文件长度 cOQy|v`KD,  
public long getFileSize() UU;:x"4  
{ ht |r+v-  
int nFileLength = -1; >`:+d'Jv0  
try{ 66*o2D\Q*G  
URL url = new URL(siteInfoBean.getSSiteURL()); PwW@I~@>  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^XM;D/Gp~  
httpConnection.setRequestProperty("User-Agent","NetFox"); ]`prDw'  
m C Ge*V}  
Q Y'-]  
int responseCode=httpConnection.getResponseCode(); I,eyL$x  
if(responseCode>=400) 5o/rV.I  
{ Jy_'(hG  
processErrorCode(responseCode); d eg>m?Y  
return -2; //-2 represent access is error g8Z14'Ke  
} Eg*3**gTO  
^U}0D^jDeE  
o[#a}5Y  
String sHeader; z"3c+?2  
(zBQ^97]  
Z3dd9m#.]  
for(int i=1;;i++) oK6lCGM5  
{ tOw 0(-:iq  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S2)S/ nf  
//Utility.log(in.readLine()); _LNPB$P  
sHeader=httpConnection.getHeaderFieldKey(i); 7;NV 1RV  
if(sHeader!=null) ^&iV%vQ[  
{ dK: "  
if(sHeader.equals("Content-Length")) e`r;`a&  
{ {P&^Erx  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader));  o 2  
break; 37xxVbik  
} kg@h R}  
} F6p1 VFs  
else {%{GZ  
break; Ao T7sy7  
} L])w-  
} jhv1 D' >6  
catch(IOException e){e.printStackTrace ();} cqx1NWlY  
catch(Exception e){e.printStackTrace ();} \]xYV}(FO  
h>:RCpC  
"zbE  
Utility.log(nFileLength); 5H+k_U  
k 5D'RD  
;L2bC3  
return nFileLength; \aIy68rH,  
} %%6 ('wi  
c'";3 6y  
)/"7$2Aoy  
//保存下载信息(文件指针位置) &F_rg,q&_  
private void write_nPos() 31& .Lnq  
{ u9w&q^0dqG  
try{  c^s>  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ,rQ)TT  
output.writeInt(nStartPos.length); 'qAfei']  
for(int i=0;i<nStartPos.length;i++) r%d 11[z  
{ a}fClI-u  
// output.writeLong(nPos); p^P y,  
output.writeLong(fileSplitterFetch.nStartPos); OPW"AB J  
output.writeLong(fileSplitterFetch.nEndPos); ,<b|@1\k  
} /T[ICd2J  
output.close(); CDj Dhs  
} e"#D){k#  
catch(IOException e){e.printStackTrace ();} &pjV4m|j<  
catch(Exception e){e.printStackTrace ();} ~aAJn IO  
} Y,btL'[W  
!" %sp6Wc  
mthl?,I|  
//读取保存的下载信息(文件指针位置) o '/C$E4W  
private void read_nPos() 3^> a TU<Z  
{ od*Z$Hb>'  
try{ vN:[  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uz3pc;0LPY  
int nCount = input.readInt(); xY2_*#{.  
nStartPos = new long[nCount]; *)1Vs'!-  
nEndPos = new long[nCount]; Wxau]uix  
for(int i=0;i<nStartPos.length;i++) [P=[hj;  
{ g)qnjeSs]  
nStartPos = input.readLong(); ^85n9a?8  
nEndPos = input.readLong(); 8zDH<Gb  
} ApYud?0b  
input.close(); x ;,xd  
} d`uO7jlm  
catch(IOException e){e.printStackTrace ();} v9m;vWp  
catch(Exception e){e.printStackTrace ();} Tw;qY  
} WwtE=od  
D"4&9"CU  
V9u\;5oL  
private void processErrorCode(int nErrorCode) 86fK= G:>  
{ NjN?RB/5  
System.err.println("Error Code : " + nErrorCode); -MU.Hu  
} nDB 2>J  
cO+Xzd;838  
"%''k~UD 4  
//停止文件下载 D%UZ'bHN*  
public void siteStop() e ]o'i;I  
{ =yX&p:-&  
bStop = true; r>~d[,^$m4  
for(int i=0;i<nStartPos.length;i++) V!77YFen %  
fileSplitterFetch.splitterStop(); Y%:0|utQC  
5b1uD>,;y  
rjHIQC C  
} uk[< 6oxz  
} 8+ F}`lLA  
//负责部分文件的抓取 D`:d'ow~KQ  
**FileSplitterFetch.java uO@3vY',n  
*/ D&l ,SD  
package NetFox; Secq^#]8  
xVkTRCh  
{XD/8m(hN|  
import java.io.*; 2FIR]@MQd  
import java.net.*; E<Dh_K  
bLEATT[  
_gm?FxV:  
public class FileSplitterFetch extends Thread { n<<=sj$\!  
)w2K&Zr0  
J4v0O="  
String sURL; //File URL gZlw  
long nStartPos; //File Snippet Start Position \D U^idp#  
long nEndPos; //File Snippet End Position xDGS`U  
int nThreadID; //Thread's ID guOSO@  
boolean bDownOver = false; //Downing is over PN"8 Y  
boolean bStop = false; //Stop identical .6ngo0<g   
FileAccessI fileAccessI = null; //File Access interface QhX C>)PW  
a=*ALd_&0  
MuoctW  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;=-j;x  
{ 6L,lq;  
this.sURL = sURL; R'I_xjC  
this.nStartPos = nStart; a We Bav}_  
this.nEndPos = nEnd; >*= =wlOB  
nThreadID = id; q)V1{B@  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %U5P}  
} O5qW*r'  
%x}&=zx0*1  
Y62u%':X  
public void run() wY3|#P CDV  
{ b-BM"~N'  
while(nStartPos < nEndPos && !bStop) o)#q9Vk%b  
{ Seq]NkgY  
~llMrl7  
~|'y+h89  
try{ w3<"g&n|  
URL url = new URL(sURL); :'y{dbKp"  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x*h`VS(?6  
httpConnection.setRequestProperty("User-Agent","NetFox"); d]CviQUq  
String sProperty = "bytes="+nStartPos+"-"; 97Zk P=Cq  
httpConnection.setRequestProperty("RANGE",sProperty); p:JRQT"A  
Utility.log(sProperty); hD6JW-  
L$lo~7<]  
tS (i711  
InputStream input = httpConnection.getInputStream(); 6h2x~@  
//logResponseHead(httpConnection); t{Hh&HX  
9^PRX  
22GnbA7O  
byte[] b = new byte[1024]; =! N _^cb  
int nRead; <AMb!?Obh  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E7gHi$  
{ -@SOo"P  
nStartPos += fileAccessI.write(b,0,nRead); < TR/ `  
//if(nThreadID == 1) my ;  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ik2- OM  
} +ze}0lrEL  
CF|moc:;  
m<4s*q0\i  
Utility.log("Thread " + nThreadID + " is over!"); V$dJmKg  
bDownOver = true; G@!_ZM8h  
//nPos = fileAccessI.write (b,0,nRead); g\o{}Q%X  
} .-SF$U_P*a  
catch(Exception e){e.printStackTrace ();} N7*CP|?E  
} ]*2EK9<  
} L\b]k,Ksf  
_%wK}eH+sy  
-G],H)M  
//打印回应的头信息 gX@nPZjg  
public void logResponseHead(HttpURLConnection con) (0E U3w?]  
{ Vk-W8[W 7  
for(int i=1;;i++) ~reQV6oQua  
{ .3{[_iTM  
String header=con.getHeaderFieldKey(i); 2{t)DUs  
if(header!=null) {)B9Z I{+A  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'e.q 7Jpd  
Utility.log(header+" : "+con.getHeaderField(header)); w"cM<Ewu  
else 4%wq:y< )/  
break; $D QD$  
} f?%qUD_#  
} `'p`PyMt`  
rI0)F  
rIeM+h7Wn  
public void splitterStop() :E>&s9Yj?  
{ ybZ}  
bStop = true; ]alh_U  
} [_WI8~g Y  
g4N%PV8  
jHAWK9fa  
} /M3y)K`^  
ku{XW8  
cz2,",+~  
/* \O kc5;kB2  
**FileAccess.java S dIGU[fm  
*//文件访问(定位,写) /Q?~Q0{)es  
package NetFox; dgS4w@)@V;  
import java.io.*; )xB$LJM8  
dh&W;zs  
TdQ ]G2  
public class FileAccessI implements Serializable{ :T_'n,  
|d $1wr  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 =G( *gx  
RandomAccessFile oSavedFile; 6nh]*/  
long nPos; X[V?T>jsM  
yeh8z:5Z O  
RcgRaQ2^  
public FileAccessI() throws IOException !\CG,Ek  
{ CN7 k?JO<  
this("",0); Q0pzW:=s]  
} hUVk54~l  
i{8]'fM  
16I&7=S,  
public FileAccessI(String sName,long nPos) throws IOException H(G!t`K  
{ %a5t15 9  
oSavedFile = new RandomAccessFile(sName,"rw"); 7p^@;@V  
this.nPos = nPos; ~<n(y-P^  
oSavedFile.seek(nPos); >;)2NrJV  
} h$70H^r  
9b1?W?"  
Bi e?M  
public synchronized int write(byte[] b,int nStart,int nLen) SD?BM-&~  
{ A2y6UzLYD  
int n = -1; 2B-.}OJ  
try{ m}98bw  
oSavedFile.write(b,nStart,nLen); rFo\+//  
n = nLen; }sv!=^}BY3  
} h40'@u^W  
catch(IOException e) a mqOxb  
{ "OO96F  
e.printStackTrace (); U^[<  
} %y>+1hakkX  
=_[2n?9y  
u?F (1iN =  
return n; =p]mX )I_  
} Y]N~vD  
+0J@y1  
|xh&p(  
} Z==!C=SBv  
GM](=|F  
s`"OM^[-  
/* f')c/Yw  
**SiteInfoBean.java jyi FM5&  
*/ 1HhX/fpq  
package NetFox; ]ni6p&b>  
)\wuesAO  
abBO93f^  
public class SiteInfoBean { #$FrFU;ZR  
_#!U"hkH  
7R,qDp S  
private String sSiteURL; //Site's URL OUzR@$  
private String sFilePath; //Saved File's Path i^*M^P3m  
private String sFileName; //Saved File's Name thuRNYv <  
private int nSplitter; //Count of Splited Downloading File S ZlC4=6c  
1Dq<{;rWb  
bhD ~ 4Rz  
public SiteInfoBean() Ry z?v<)h  
{//nSplitter的缺省值为5 +3;Ody"59  
//default value of nSplitter is 5 %ISq>A)%  
this("","","",5); }B0sC%cm  
} rfs(#  
 GP+2/D  
TnNWO+ kg  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HY;9?KJ'  
{ .k@^KY  
sSiteURL= sURL; gfde#T)S  
sFilePath = sPath; ?`"n3!>bS  
sFileName = sName; 8Atq,GcG  
this.nSplitter = nSpiltter; H<`\bej,  
;3;2h+U*  
;L~p|sF  
} }3Y <$YL"R  
_A{+H^,  
ZQAO"huk]  
public String getSSiteURL() :"<e0wDu[  
{ @'i+ff\  
return sSiteURL; ;F5"}x  
} R)oB!$k  
%<} <'V0  
fW(/Loh  
public void setSSiteURL(String value) @vRwzc\   
{ ]78!!G[`  
sSiteURL = value; pYo=oI  
} W;zpt|kAH  
XA<ozq'  
XJgh>^R^  
public String getSFilePath() h?Nek+1'  
{ >{5 p0  
return sFilePath; \\:|Odd  
} &nY;=Hv`WY  
r\2vl8X~  
5Fbs WW2  
public void setSFilePath(String value) 2q PhLCe Z  
{ :et#0!  
sFilePath = value; 2-dh;[4  
} 3K>gz:dt  
kz B\'m,l  
khx.yRx  
public String getSFileName() raE Mm  
{ 19c@`?  
return sFileName; 2&he($HIzg  
} ^m!_ 2_q  
sw;|'N$:<  
:,S98z#  
public void setSFileName(String value) z.oU4c  
{ .[:VSM7T  
sFileName = value; 8{0k0 &x  
} :Q_3hK  
%S@L|t  
M`7y>Ud  
public int getNSplitter() F~HRME; Z  
{ 5o)Y$>T0  
return nSplitter; 8Pmdk1 ~  
} 0;<)\Wt=i9  
!GwL,)0@^  
-Z0+oU(?YE  
public void setNSplitter(int nCount) J !HjeZ  
{ g(Yb^'X/  
nSplitter = nCount; *?t%0){  
} A"uULfnk  
} 65TfFcQ<S  
&GhPvrxI?  
CnISe^h  
/* uw AwWgl  
**Utility.java G[,Q95`w?<  
*/ wN=;i#  
package NetFox; S($Su7g%_  
0 1V^L}  
iW%8/$  
public class Utility { R=]d%L8  
x Q4%e[/  
u92^(|  
public Utility() xSMt*]=9  
{ N&,]^>^u  
fv!?Ga(  
-/P\"c  
} p H@]Y+W  
SaOYu &>  
//线程睡眠 \%0n}.A  
public static void sleep(int nSecond) Gl}Qxv#$  
{ j%IF2p2  
try{ Oy57$  
Thread.sleep(nSecond); CGbwmPx  
} @FO) 0  
catch(Exception e) wkUlrL/~  
{ LR(-<"  
e.printStackTrace (); 4_/?:$KO  
} 5PT5#[  
} MGJ.,tK1  
k8AW6oO/i  
//日志 n'1'!J; Q  
public static void log(String sMsg) yQNV@T<o  
{ P"/G  
System.err.println(sMsg); IZ/m4~  
} k,yZ[n|`  
5=|hC3h  
j|4C\~i  
public static void log(int sMsg) )wvHGecp*  
{ Ho;X4lo[j  
System.err.println(sMsg); yQ,{p@#X8  
} V[o`\|<  
} ,Wbwg  
*)M49a*UD  
Gh.[dF?  
/* 6( CDNMzj  
**TestMethod.java 6!'3oN{  
*/ BZ!v%4^9  
package NetFox; ;!!n{l$r'  
&-d&t` `  
9H-|FNz?c  
public class TestMethod { %a+mk E  
G+UMBn  
\R36w^c3  
public TestMethod() #X 52/8G  
{ ///xx/weblogic60b2_win.exe j)C,%Ol  
try{ H,nec<Jp  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); o%9*B%HO/  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {(U %i\F\  
SiteFileFetch fileFetch = new SiteFileFetch(bean); {!t7[Ctb  
fileFetch.start(); eq(am%3~  
} fk1ASV<rN  
catch(Exception e){e.printStackTrace ();} }X*Riu7gk  
li~d?>  
I M-L'9  
} (3J$>Na  
Szbb_i{_ `  
}J">}j]/  
public static void main(String[] args) tg]x0#@s  
{ 26&'X+n&  
new TestMethod(); &0 >Loja`^  
} R}^~^#  
}  ks$JP6  
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