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http断点续传简单实现(java)

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/* DWQQ615i  
**SiteFileFetch.java #Hi]&)p_  
*/ o '/C$E4W  
package NetFox; 3^> a TU<Z  
import java.io.*; od*Z$Hb>'  
import java.net.*; vN:[  
)C]&ui~1  
xY2_*#{.  
public class SiteFileFetch extends Thread { ROS"VV<  
g ypq`F  
[P=[hj;  
SiteInfoBean siteInfoBean = null; //文件信息Bean o!`O i5  
long[] nStartPos; //开始位置 ><Z3<7K9  
long[] nEndPos; //结束位置 n~u3  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 {$YD-bqY  
long nFileLength; //文件长度 ih |Ky+!  
boolean bFirst = true; //是否第一次取文件 F LI8r:  
boolean bStop = false; //停止标志 p''"E$B/(  
File tmpFile; //文件下载的临时信息  F'FZ?*a  
DataOutputStream output; //输出到文件的输出流 lk1Gs{(qhH  
@B[Cc`IN"  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) \&&(ytL  
public SiteFileFetch(SiteInfoBean bean) throws IOException ) Zo_6%  
{ NjN?RB/5  
siteInfoBean = bean; L8wcH  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); -MU.Hu  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); heZy 66  
if(tmpFile.exists ()) Q4Fq=kTE  
{ 6\fMzm  
bFirst = false; RS `9?c:  
read_nPos(); U!?gdX  
} 5}bZs` C  
else ikN!ut  
{ 8<g#$(a_E  
nStartPos = new long[bean.getNSplitter()]; exO#>th1  
nEndPos = new long[bean.getNSplitter()]; ~vSAnjeR  
} zX [ r  
fTV|? :C{  
92]ZiL?k  
_T|H69 J  
} E\~ KVn  
ITIj=!F*  
|W*@}D  
public void run() %=9yzIjbAt  
{ uO@3vY',n  
//获得文件长度 D&l ,SD  
//分割文件 ()M@3={R  
//实例FileSplitterFetch 7k=F6k0)  
//启动FileSplitterFetch线程 >q@Sd  
//等待子线程返回 MiH}VfI  
try{ 6w"( y~c1  
if(bFirst) 7X{bB  
{ bLEATT[  
nFileLength = getFileSize(); _gm?FxV:  
if(nFileLength == -1) BBR" HMa4  
{ &49$hF g6"  
System.err.println("File Length is not known!"); I+"?,Ej$K  
} $.Q>M]xH  
else if(nFileLength == -2) R G0S  
{ p&sK\   
System.err.println("File is not access!"); VkDS&g~Ws  
} XQ 3*  
else 4Kn9*V  
{ mvq7G  
for(int i=0;i<nStartPos.length;i++)  6Z&u  
{ ]osx.  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ]TBtLU3  
} Bug}^t{M  
for(int i=0;i<nEndPos.length-1;i++) YYE8/\+B.  
{ Z@,PZ   
nEndPos = nStartPos[i+1]; {!}F :~*r  
} w^])(  
nEndPos[nEndPos.length-1] = nFileLength; G_M:0YI@  
} (#bp`Kih  
} l{6` k<J(  
=,4 '"  
K6v $#{$6  
//启动子线程 aM{@1m Bm  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Seq]NkgY  
for(int i=0;i<nStartPos.length;i++) i#RElH  
{ P}hY {y'  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Z.:<TrN  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q^lQi\[  
nStartPos,nEndPos,i); kOAY@a  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UXwB$@8  
fileSplitterFetch.start(); B)rr7B  
} PW*;Sp  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,rZn`9  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 5:%..e`T  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", B6ed,($&  
nEndPos = " + nFileLength); g=xv+e  
// fileSplitterFetch[nPos.length-1].start(); au~]  
9p2>`L  
6Lg!L odu  
//等待子线程结束 @A2/@]HBm  
//int count = 0; )WVItqQKV  
//是否结束while循环 VFl 1 f  
boolean breakWhile = false; B;GxfYj  
L1 9 MP  
x2C/L  
while(!bStop) =t3vbV  
{ N.0HfYf  
write_nPos(); Ht|",1yr+  
Utility.sleep(500); $N;"}G z  
breakWhile = true; >*`>0Q4y  
?ds f@\  
3}B5hht "D  
for(int i=0;i<nStartPos.length;i++) ADYx.8M|9i  
{ 8cK\myn.  
if(!fileSplitterFetch.bDownOver) =w ^TcV  
{ lf%b0na?r  
breakWhile = false; >f\zCT%cf  
break; -BA"3 S  
} fJLf7+q  
} #\pP2  
if(breakWhile) b JfD\  
break; # 0GGc.  
I9}+(6  
:tMre^oP  
//count++; 3P//H8 8LY  
//if(count>4) [d4,gEx`Q\  
// siteStop(); ORowx,(hX  
} 4}Q O!(  
'7xxCj/*  
':l"mkd+`  
System.err.println("文件下载结束!"); f?%qUD_#  
} `'p`PyMt`  
catch(Exception e){e.printStackTrace ();} (2z%U  
} m|]j'g?{}(  
rDVgk6  
}RcK_w@Jx)  
//获得文件长度 (8CCesy&  
public long getFileSize() \!^i;1h0c3  
{ m[Z6VHn  
int nFileLength = -1; uR#'lb`3  
try{ ^^G-kg  
URL url = new URL(siteInfoBean.getSSiteURL()); .OmQ'  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?k{|Lk  
httpConnection.setRequestProperty("User-Agent","NetFox"); L5Urg*GNL  
- <J q  
4~O6$;!|~  
int responseCode=httpConnection.getResponseCode(); Zc-#;/b3T  
if(responseCode>=400) GAv)QZyV$  
{ S8O)/Sg=  
processErrorCode(responseCode); 9>N\sOh  
return -2; //-2 represent access is error u4:\UC'  
} $ !v}xY  
tM&n3MWQ  
\n#]%X5c  
String sHeader; }0QN[$H!  
f hQy36i@  
'pan9PW  
for(int i=1;;i++) }>V/H]B  
{ MZT6g.ny  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); NMXnrvS&  
//Utility.log(in.readLine()); hUVk54~l  
sHeader=httpConnection.getHeaderFieldKey(i); i{8]'fM  
if(sHeader!=null) |~SE"  
{ I>{!U$  
if(sHeader.equals("Content-Length")) H(G!t`K  
{ %a5t15 9  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); tXt:HVN  
break; 7))\'\  
} -b cG[W3  
} \a"i7Caa  
else oEJaH  
break;  ]nUR;8  
} cTM$ZNin  
} vYDSu.C@a  
catch(IOException e){e.printStackTrace ();} &vCeLh:s  
catch(Exception e){e.printStackTrace ();} ]/Vh{d|I&  
);nz4/V  
 kI%peb?  
Utility.log(nFileLength); UP\C"\  
OU!nN>ln  
0<g<GQ(E  
return nFileLength; & g:%*>7P  
} U^[<  
%y>+1hakkX  
=_[2n?9y  
//保存下载信息(文件指针位置) ~LbS~_\C=  
private void write_nPos() O#Z/+\U  
{ gmY/STN   
try{ a:A n=NA  
output = new DataOutputStream(new FileOutputStream(tmpFile)); IAf$]Fh  
output.writeInt(nStartPos.length); .`,F  
for(int i=0;i<nStartPos.length;i++) Uo2+:p  
{ KbAR_T1n  
// output.writeLong(nPos); &y7 0  
output.writeLong(fileSplitterFetch.nStartPos); L\YKdUL  
output.writeLong(fileSplitterFetch.nEndPos); 8h|M!/&2  
} Bz+.Qa+  
output.close(); 0#QKVZq2>  
} p%F8'2)}  
catch(IOException e){e.printStackTrace ();} ;hwzYXWF  
catch(Exception e){e.printStackTrace ();} !tU'J"Zy  
} !6H uFf  
PL@~Ys0  
FEF"\O|Q  
//读取保存的下载信息(文件指针位置) i^*M^P3m  
private void read_nPos() /s:w^ g~  
{ &|b4\uj9  
try{ Q&xjF@I  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `FZF2.N  
int nCount = input.readInt(); %zzYleJ!]  
nStartPos = new long[nCount]; kn}z gSO  
nEndPos = new long[nCount]; o@9+mM"B)  
for(int i=0;i<nStartPos.length;i++) g:_hj_1Y M  
{ }B0sC%cm  
nStartPos = input.readLong(); rfs(#  
nEndPos = input.readLong(); >GXXjAIu/  
} /Pvk),ca  
input.close(); :&qhJtGo  
} k#C f})  
catch(IOException e){e.printStackTrace ();} GAw(mH*  
catch(Exception e){e.printStackTrace ();} 2ev*CX6.  
} =q+R   
BX[~% iE  
edijfhn  
private void processErrorCode(int nErrorCode) R,F gl2  
{ %X>FVlPm  
System.err.println("Error Code : " + nErrorCode); gO='A(Y  
} ]tB@kBi "  
U\jb"  
Fu7M0X'p  
//停止文件下载 fN)x#?  
public void siteStop() T|;@ T^  
{ R)oB!$k  
bStop = true; *%\mZ,s"  
for(int i=0;i<nStartPos.length;i++) S/4r\6  
fileSplitterFetch.splitterStop(); jvHFFSK  
NQX>Qh 2  
?[)yGRzO2  
} Kb&V!#o)  
} v vq/  
//负责部分文件的抓取 sb^mLH] 3  
**FileSplitterFetch.java ZyI$M3{J  
*/ +j{Y,t{4  
package NetFox; eY,O@'"8`  
BLn_u,3  
?59'dGnz_  
import java.io.*; l%~lz[  
import java.net.*; @g-G =Ba  
yK1ie  
PcC/_+2  
public class FileSplitterFetch extends Thread { nPFwPk8=M  
"R[l ZJ@  
E]I$}>k  
String sURL; //File URL j*400  
long nStartPos; //File Snippet Start Position ^lj7(  
long nEndPos; //File Snippet End Position  $dQIs:  
int nThreadID; //Thread's ID mR% FqaN_  
boolean bDownOver = false; //Downing is over }D*yr3b  
boolean bStop = false; //Stop identical <*(^{a. O  
FileAccessI fileAccessI = null; //File Access interface :,S98z#  
oC*=JJe,  
gL3iw!7  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException BT,b-= ;J-  
{ \X|sU:g  
this.sURL = sURL; h|bT)!|  
this.nStartPos = nStart; Kqg!,Sn|  
this.nEndPos = nEnd; eC! #CK  
nThreadID = id; 3mO;JXd  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c_.-b=zm  
} ""% A'TZ  
4)kG-[#  
.Z\Q4x#!Z  
public void run() w1 `QIv  
{ T2FE+A]n9  
while(nStartPos < nEndPos && !bStop) g(Yb^'X/  
{ ,Na^%A@TJ  
AjkW0FB:1  
V'DA[{\*  
try{ "OmD@ EMT  
URL url = new URL(sURL); 9Uf j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DinPxtT?a  
httpConnection.setRequestProperty("User-Agent","NetFox"); 9\JQ7$B  
String sProperty = "bytes="+nStartPos+"-"; SA;#aj}rV  
httpConnection.setRequestProperty("RANGE",sProperty); R>/ NE!q  
Utility.log(sProperty); ,q#0hy%5/  
]:ZdV9`  
upy\gkpnGO  
InputStream input = httpConnection.getInputStream(); i7*EbaYzUO  
//logResponseHead(httpConnection); IiJZ5'{  
lg$zGa?  
y<:<$22O  
byte[] b = new byte[1024]; z>m=h)9d~  
int nRead; ^D{lPu 3  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -/P\"c  
{ p H@]Y+W  
nStartPos += fileAccessI.write(b,0,nRead); ][&9]omB  
//if(nThreadID == 1) LWfqEL -  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !bnyJA  
} BU|#e5  
O|kOI?f  
T,%j\0  
Utility.log("Thread " + nThreadID + " is over!"); K`g7$r)U[  
bDownOver = true; n.}E5 %qK  
//nPos = fileAccessI.write (b,0,nRead); Cbm\h/PXl  
} p-GAe,2q  
catch(Exception e){e.printStackTrace ();} T;5r{{  
} )%d*3\Tsd  
} PG~$D];  
CW&.NT  
eHiy,IN  
//打印回应的头信息 47K1$3P  
public void logResponseHead(HttpURLConnection con) 9(4&KZpK  
{ ~;]W T  
for(int i=1;;i++) nkfZiyx  
{ eWJ`$"z  
String header=con.getHeaderFieldKey(i); *{ {b~$  
if(header!=null) kM8{C w  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v\tEVhm  
Utility.log(header+" : "+con.getHeaderField(header)); g%[c<l9  
else #_93f |  
break; 06q(aI^Ch@  
} -G7TEq)  
} s$D ^>0  
7*5Z  
Jg}K.1Hs  
public void splitterStop() T~0k"uTE  
{ ;!!n{l$r'  
bStop = true; (xHf4[[u  
} 9H-|FNz?c  
z`UhB%-?  
>TkE~7?l  
} pi<TFe@eG  
anMF-x4/*q  
jRSUp E8  
/* }|u4 W?H  
**FileAccess.java Qv,"($n\  
*//文件访问(定位,写) y*pUlts<  
package NetFox; l*\y  
import java.io.*; aI^/X {d  
}G4 z tiuG  
}XO K,Hw  
public class FileAccessI implements Serializable{ /='. 4 v  
]vWKR."4  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 VXIP0p@  
RandomAccessFile oSavedFile; 2EZb )&Q  
long nPos; Y2o?gug  
3b'QLfU&#  
g L_Y,A~Q{  
public FileAccessI() throws IOException 3 @ak<9&  
{ 'u4<BQVV[  
this("",0); }by;F9&B  
}  ks$JP6  
u/cg|]x&T  
q\m2EURco  
public FileAccessI(String sName,long nPos) throws IOException $,+O9Et  
{ ),G=s Oo  
oSavedFile = new RandomAccessFile(sName,"rw");  #wL  
this.nPos = nPos; OQW#a[=WQ  
oSavedFile.seek(nPos); T}V!`0vKw  
} M`rl!Ci#  
91 =OF*w  
n2)q}_d  
public synchronized int write(byte[] b,int nStart,int nLen) 3s/H2f z  
{ fF b_J`'ue  
int n = -1; 3;S, 3  
try{ Tb3J9q+ya  
oSavedFile.write(b,nStart,nLen); O+y-}7YX  
n = nLen;  J5^'HU3  
} &boOtl^  
catch(IOException e) 8GvJ0Jq}U  
{ rM'=_nmi  
e.printStackTrace (); 5R(/Uiv3F  
} \,u_7y2 c  
u%w`:v7Yo(  
{&jb5-*f  
return n; v?KC%  
} M$Zcn#A  
bGc~Wr|  
Vx~,Uex0+  
} O3I8k\`  
uc;8 K,[t  
n4}B r;%  
/* tmQH|'>>  
**SiteInfoBean.java gb H<]?  
*/ xlhG,bb7  
package NetFox; $GlWf  
b )B? F  
{q"OM*L(  
public class SiteInfoBean { zT!drq:x  
W[Ls|<Q  
{phNds%  
private String sSiteURL; //Site's URL q WQ/ 'M  
private String sFilePath; //Saved File's Path e" St_z(  
private String sFileName; //Saved File's Name j'A_'g'^  
private int nSplitter; //Count of Splited Downloading File dBz/7&Q   
7=;R& mqC  
Z'"tB/=W  
public SiteInfoBean() :]\([Q+a  
{//nSplitter的缺省值为5 a(l29>  
//default value of nSplitter is 5 _d5QbTe  
this("","","",5); "wNJ  
} 9I}-[|`u  
Zl^\Q=*s  
etTn_v  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r>o63Q:  
{ D)L+7N0D~  
sSiteURL= sURL; [ucpd  
sFilePath = sPath; '.:z&gSqx0  
sFileName = sName; `{dm;j5/y  
this.nSplitter = nSpiltter; XD.)Dl8  
wne,e's}   
LDPUD'  
} `aciXlqIF  
Lm%:K]X  
'<"s \,  
public String getSSiteURL() G3Z)Z) N  
{ ` @`CG[-9  
return sSiteURL; KV(Q;~8"X  
} >CHrg]9  
U~:-roQ(\  
17%Mw@+  
public void setSSiteURL(String value) hb}+A=A=+  
{ g:hjy@ w  
sSiteURL = value; 5>[u `  
} ?8'*,bK  
~"nxE  
.+$ Q<L  
public String getSFilePath() <3LbN FP  
{ 45@^L's  
return sFilePath; x(1:s|Uyp{  
} I>W=x'PkLn  
6 (]Dh;gC  
_852H$H\  
public void setSFilePath(String value) EV]1ml k$  
{  y3@H/U{  
sFilePath = value; s~^5kgPA  
} ;r<^a6B  
F1*>y  
dYJ(!V&  
public String getSFileName() y [}.yyye  
{ IG2r#N|C#  
return sFileName; F3On?x)  
} Te"ioU?.  
$a.JSXyxL  
v[1aW v:  
public void setSFileName(String value) Kp%2k^U  
{ G<65H+)M\  
sFileName = value; >qnko9V  
} wW>A_{Y  
d; boIP`M;  
xF!,IKlBBp  
public int getNSplitter() LSL/ZvSP  
{ akp-zn&je  
return nSplitter; =$'6(aDH  
} f6hnTbJ  
ldU?{o:\s  
h4fJvOk|!  
public void setNSplitter(int nCount) p`olCp'  
{ lXW%FH6c+  
nSplitter = nCount; c"f-3kFv  
} 6' k<+IR  
} b RFLcM  
y%"{I7!A  
XP!S$Q]D  
/* mE+*)gb:Rd  
**Utility.java ~Y^+M*   
*/ Sc]B#/~B  
package NetFox; ?WGA?J %2  
"H'B*vc-  
J!dm-L  
public class Utility { D+lAhEN  
~~D{spMVO  
ZgTW.<.%2  
public Utility() {'7B6  
{ - YEZ]:"  
ha]VWt%}  
*& BQTZ6  
} xQ f*  
BtkOnbz8X  
//线程睡眠 Ri<u/ ]oR"  
public static void sleep(int nSecond) )1?y 8_B  
{ 3Z>Ux3[  
try{ cuax;0{%  
Thread.sleep(nSecond); |mZxfI  
} Ytn9B}%o  
catch(Exception e) KI"#f$2&  
{ Z9v31)q(  
e.printStackTrace (); 01 }D,W`  
} hNC&T`.-~B  
} g|o,uD  
S|Q@:r"  
//日志 P_F30 x(  
public static void log(String sMsg) lU8l}Ndz"  
{ (p"%O  
System.err.println(sMsg); 4>wP7`/+y  
} R$R *'l  
!z\h| wU+  
\1k79c  
public static void log(int sMsg) Hus)c3Ty7  
{ '{cIAw/"n  
System.err.println(sMsg); E^ B'4  
} L^1NY3=$  
} R)c?`:iUB  
A#e%^{q$  
Tf>bX_L?  
/* XY5K%dMU  
**TestMethod.java 'p^t^=dQ  
*/ \[;0 KV_  
package NetFox; 5?f ^Rz  
Akq2 d;  
NDN7[7E  
public class TestMethod { nGC/R&  
^}RCoE  
%Hu5K>ZNYp  
public TestMethod() VF+KR*  
{ ///xx/weblogic60b2_win.exe Sj3+l7S?  
try{ a1T'x~ '  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aS>u,=C  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); D(~U6SR  
SiteFileFetch fileFetch = new SiteFileFetch(bean); %Tfbsyf%f  
fileFetch.start(); ]=\].% >  
} H%[eV8  
catch(Exception e){e.printStackTrace ();} C"y(5U)d  
dn& s*  
 {y)=eX9  
}  CT&|QH{  
b!+hH Hv:  
-M\<nx  
public static void main(String[] args) 4j-Xi  
{ x[cL Bc<  
new TestMethod(); n'"/KS+_  
} R|'ybW'Y  
} AzPu)  
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