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http断点续传简单实现(java)

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/* Y~6pJNR  
**SiteFileFetch.java 5V0=-K  
*/ ~oI49Q&{  
package NetFox; uH#NJoR O  
import java.io.*; ?#'qY6 ^  
import java.net.*; )Jc>l;G(M  
8"@<s?0\"  
>cp9{+#f  
public class SiteFileFetch extends Thread { 19EU[eb  
T]xGE   
Vswi /(  
SiteInfoBean siteInfoBean = null; //文件信息Bean 9fiZ5\  
long[] nStartPos; //开始位置 > h9U~#G=  
long[] nEndPos; //结束位置 :A$6Y*s\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 <j>@Fg#q  
long nFileLength; //文件长度 ">o/\sXeH  
boolean bFirst = true; //是否第一次取文件 :/3`+&T^/  
boolean bStop = false; //停止标志 AYi$LsLhO  
File tmpFile; //文件下载的临时信息 ^V:YNUqp#  
DataOutputStream output; //输出到文件的输出流 cA*%K[9  
s-*XAn ot  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) QqDF_  
public SiteFileFetch(SiteInfoBean bean) throws IOException d09GD[5  
{ 5IepVS(>?v  
siteInfoBean = bean; 75F&s,4+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); #O~Y[''C5X  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); U{x'@/Ld  
if(tmpFile.exists ()) ;r y{cq  
{ y|aWUX/a  
bFirst = false; %F7aFvl*  
read_nPos(); %tMfOW  
} B}Qo8i7 z  
else g N[r*:B  
{ [  /D/  
nStartPos = new long[bean.getNSplitter()]; B[$e;h*Aw[  
nEndPos = new long[bean.getNSplitter()]; 5Ql6?U HD  
} IoX(Pa  
, R)[$n  
(X8N?tJ  
^\!^#rO  
} ql8:s>1T  
PyoLk  
%6n;B|!  
public void run() Z` Aiw."|  
{ 6QV/8IX  
//获得文件长度 #8`G&S*  
//分割文件 P)H%dJ ^l  
//实例FileSplitterFetch 9> |rIw  
//启动FileSplitterFetch线程 YP6+o#==  
//等待子线程返回 V6!oe^a7'  
try{ 5!Guf?i  
if(bFirst) ^,X+ n5q;m  
{ Y5;:jYk#<_  
nFileLength = getFileSize(); D Lu]d$G  
if(nFileLength == -1) [AU1JO`\"  
{ >8,BC  
System.err.println("File Length is not known!"); O-7 \qz  
} Cr&ua|%F  
else if(nFileLength == -2) T7,tJk,(  
{ JvG t=v  
System.err.println("File is not access!"); |9g*rO  
} u&<LW4  
else WgjaMmht  
{ X:dj5v  
for(int i=0;i<nStartPos.length;i++) YziQU_  
{ CN >q`[!  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); A_g'9  
} )TWf/L cp  
for(int i=0;i<nEndPos.length-1;i++) MF1u8Yl:0  
{ [fb-G5x  
nEndPos = nStartPos[i+1]; =#W{&Te;  
} 3B_S>0H"$  
nEndPos[nEndPos.length-1] = nFileLength; 41:Z8YL(  
} 7#RW4ZM  
} o(a*Fk$  
AXJC&O}`  
!~RD>N&n  
//启动子线程 OZ-F+#d  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }3+(A`9h f  
for(int i=0;i<nStartPos.length;i++) CocvEoE*z  
{ y_'8m9Qy)  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gh~C.>W}q+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?6[>HX;  
nStartPos,nEndPos,i); R)H@'X  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X4o8  
fileSplitterFetch.start(); 4(Mt6{q  
} 0!^{V:DtQ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R; IB o  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 4iKT  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X`22Hf4ct  
nEndPos = " + nFileLength); DZ EA*E>  
// fileSplitterFetch[nPos.length-1].start(); ! |}>Y  
u!F3Rh8D  
YX~H!6l  
//等待子线程结束 '; qT  
//int count = 0; Z(V 4"x7F  
//是否结束while循环 tV<A u  
boolean breakWhile = false; M+ H$Jjcs  
+x WT)h/  
BtjsN22  
while(!bStop) &)wQ|{P~k  
{ j6Vuj/+}  
write_nPos(); 7%0PsF _  
Utility.sleep(500); ov|s5yH8e  
breakWhile = true; }g`A*y;t  
0z,c6MjM+  
NE/3aU  
for(int i=0;i<nStartPos.length;i++) DB?[h<^m  
{ t4,6`d?C  
if(!fileSplitterFetch.bDownOver) }U8H4B~UtY  
{ Qz $1_vO  
breakWhile = false; aZmSCi:&'  
break; '&UX'Dd~Q  
} 8(ZQD+U(9F  
} T,;6q!s=  
if(breakWhile) |vGz 1jLV  
break; zRu}lJ1#W$  
jtd{=[STU  
hmks\eb~  
//count++; (}}BZ S&.  
//if(count>4) ^d!-IL_  
// siteStop(); l_$~~z ~  
} /*st,P$"  
5<&<61[A  
b`1P%OjC  
System.err.println("文件下载结束!"); Vj`9j. 5  
} 1z{Azp MZ  
catch(Exception e){e.printStackTrace ();} @1rF9< 4g  
} 'os-+m@  
Ff.gRx  
YsLEbue   
//获得文件长度 ZJd1Lx   
public long getFileSize() /SZsXaC '  
{ Z!tt(y\  
int nFileLength = -1; qA&N6`  
try{ ;c~6^s`2  
URL url = new URL(siteInfoBean.getSSiteURL()); ?e yo2:-$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e PlEd'Z  
httpConnection.setRequestProperty("User-Agent","NetFox"); , Lhgv1  
o D^],  
*"4 OXyV  
int responseCode=httpConnection.getResponseCode(); 3_ObCsJ#,  
if(responseCode>=400) ]#_,?d  
{ iv\?TAZC  
processErrorCode(responseCode); NNSn]LP  
return -2; //-2 represent access is error q1Ah!9B  
} "o% N`Xlx  
389T6sP]  
\O`B@!da~  
String sHeader; X,^J3Ek>O  
G+=&\+{#4  
' ^n2]<  
for(int i=1;;i++) &QLCij5:  
{ 7G!SlC X}W  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); IZniRd;  
//Utility.log(in.readLine()); /6b(w=pk  
sHeader=httpConnection.getHeaderFieldKey(i); pn>zuH e  
if(sHeader!=null) cKdy)T%;  
{ ]MRE^Je\h  
if(sHeader.equals("Content-Length")) QV7K~qi  
{ A\k@9w\Ll;  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j<4J_wE  
break; K4snp u hC  
} \snbU'lfP  
} 9kWyO:a_(  
else 'l)@MX bGL  
break; uXyNj2(d.  
} |s[m;Qm[ku  
} o~2bk<]z  
catch(IOException e){e.printStackTrace ();} Ds$FO}KD{  
catch(Exception e){e.printStackTrace ();} &}wKC:LSP  
c-n'F+fZ  
/%=p-By<V  
Utility.log(nFileLength); _)ZAf% f?  
m>jX4D7KZ  
JP S L-j  
return nFileLength; _LxV)  
} (/Hq8o-Fw  
r"zW=9 O=  
m%'9zL c  
//保存下载信息(文件指针位置) lKxv SyD  
private void write_nPos() rM/*_0[`d  
{ 6P3ezl@#;  
try{ m{I_E G  
output = new DataOutputStream(new FileOutputStream(tmpFile)); {M$mrmG  
output.writeInt(nStartPos.length); 76 #  
for(int i=0;i<nStartPos.length;i++) {y)s85:t  
{ M\DUx5d J,  
// output.writeLong(nPos); #}^ZxEU  
output.writeLong(fileSplitterFetch.nStartPos); )p).}"   
output.writeLong(fileSplitterFetch.nEndPos);  Xb&r|pR  
} n)8bkcZCp+  
output.close(); $Vlfg51ob  
} s"=e (ob  
catch(IOException e){e.printStackTrace ();} b=Zg1SqV  
catch(Exception e){e.printStackTrace ();} X CDHd ?Ld  
} >OBuHqC  
NGd|7S[^+c  
r9yUye}  
//读取保存的下载信息(文件指针位置) ec)G~?FH  
private void read_nPos() YEF%l'm( \  
{ OHR9u  
try{ ]j}zN2[A  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lva]jh2  
int nCount = input.readInt(); Q4Hf!v]r  
nStartPos = new long[nCount]; v'Tk Kwl  
nEndPos = new long[nCount]; B@63=a*kG  
for(int i=0;i<nStartPos.length;i++) UFyGp>/06  
{ rM2?"  
nStartPos = input.readLong(); G$x uHHZ'  
nEndPos = input.readLong(); ? Ls]k  
} /#G^?2o M  
input.close(); >6@*%LM  
} k&n7 _[]n  
catch(IOException e){e.printStackTrace ();} lF 8B+  
catch(Exception e){e.printStackTrace ();} }V ;PaX  
} @433?g`2b  
tPDV"Md#m<  
svU107?  
private void processErrorCode(int nErrorCode) ygd'Nh!@  
{ <Lyz7R6  
System.err.println("Error Code : " + nErrorCode); X:j&+d2g0/  
} F'C]OMBE  
6(ju!pE`  
o//N"S.)  
//停止文件下载 U :J~O y_Z  
public void siteStop() O8[dPm W  
{ )qzJu*cQ  
bStop = true; qusgX;)  
for(int i=0;i<nStartPos.length;i++) z }R-J/xr2  
fileSplitterFetch.splitterStop(); <$Q&n{  
Rdwr?:y(]  
R 7xV{o  
} S;Lqx5Cd  
} t1n'Ecm(  
//负责部分文件的抓取 9cQKXh:R.  
**FileSplitterFetch.java nm*1JA.:  
*/ OC 7:Dp4  
package NetFox; s,]6Lri`\  
rfXM*h  
fx99@%Ii  
import java.io.*; K%2,z3ps  
import java.net.*; 29,`2fFr  
O >n L;I  
n"@3d.21  
public class FileSplitterFetch extends Thread { 9/~m837x  
U1 1rj,7  
f$*M;|c1c/  
String sURL; //File URL P]yER9'  
long nStartPos; //File Snippet Start Position *yiJw\DRN  
long nEndPos; //File Snippet End Position O<L /m[]  
int nThreadID; //Thread's ID )n5]+VTZ5  
boolean bDownOver = false; //Downing is over MR#jI  
boolean bStop = false; //Stop identical QkGr{  
FileAccessI fileAccessI = null; //File Access interface h'MX{Wm.  
qAivsYN*  
X'7 T"5!  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException jcXb@FE6  
{ ##}a0\x|  
this.sURL = sURL; I"Ju3o?u  
this.nStartPos = nStart; ugVsp&i#  
this.nEndPos = nEnd; h+R}O9BD  
nThreadID = id; A>R ^iu  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 LL9I:^  
} V=3NIw18  
`z Z=#p/  
QTcngv[  
public void run() }{=%j~V;&  
{ x03GJy5  
while(nStartPos < nEndPos && !bStop) @ U}fvdft  
{ (0Hhn2JA  
z<: 9,wtbP  
T/-PSfbkj  
try{ Vxo3RwmR  
URL url = new URL(sURL); hYb!RRGn  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nf<([8v;t  
httpConnection.setRequestProperty("User-Agent","NetFox"); b[e+(X  
String sProperty = "bytes="+nStartPos+"-"; 0kmVP~K  
httpConnection.setRequestProperty("RANGE",sProperty); TD!QqLW  
Utility.log(sProperty); 9#O"^.Z !  
r[EN`AxDb  
#/\FB'zC  
InputStream input = httpConnection.getInputStream(); s8 .oS);`  
//logResponseHead(httpConnection); JOenVepQ,  
`.L8<-]W  
{BJ[h  
byte[] b = new byte[1024]; e0v&wSi  
int nRead; Z~T- *1V  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vi5RkUY]  
{ R0oP##]  
nStartPos += fileAccessI.write(b,0,nRead); J*a`qU   
//if(nThreadID == 1) }I05&/o.3p  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FjkE^o>  
} 0sV;TQt+f  
M ;\K+,  
L_ 8C=MS  
Utility.log("Thread " + nThreadID + " is over!"); ]%>;R^HY  
bDownOver = true; |Vd)7/LN  
//nPos = fileAccessI.write (b,0,nRead); L|!9%X0.  
} r IS \#j  
catch(Exception e){e.printStackTrace ();} Rjm5{aa-  
} <Ni]\-*  
} D?X97jNm  
J]fjg%C2m  
ec"L*l"  
//打印回应的头信息 q SCt= eQ  
public void logResponseHead(HttpURLConnection con) uysGOyi<u  
{ b4oZ@gVR;  
for(int i=1;;i++) mgH4)!Z*56  
{ 9FJU'$FN  
String header=con.getHeaderFieldKey(i); ;v8,r#4  
if(header!=null) )|Y"^K%Jm  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |`:Uww+3  
Utility.log(header+" : "+con.getHeaderField(header)); 2&Wc4,O!i  
else |}'}TYX0:  
break; ")x9A&p  
} ]%shs  
} }tc,3> /  
[S3X  
h'IBVI!P  
public void splitterStop() ~~'XY(\L@  
{ lyv9eM  
bStop = true; mIl^  
} 3smcCQA%  
6j_ A{*~Ng  
1Voo($q.  
} u8-)LOf(  
vV"TTzs!  
SGjaH 8z  
/* -$[=AqJXp;  
**FileAccess.java M7!&gFv8  
*//文件访问(定位,写) s)xfTr_$  
package NetFox; 8l;0)`PU  
import java.io.*; Z-]d_Y~m4  
qX-Jpi P  
!=k\Rr@qx  
public class FileAccessI implements Serializable{ _%Mu{Ni&  
w;r -TLf  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p5G O@^i  
RandomAccessFile oSavedFile; B^{bXhDp  
long nPos; N#]f?6 *R  
H-7*)D  
/c__{?go  
public FileAccessI() throws IOException /EKfL\3  
{ *R1x^t+)  
this("",0); 2ORWdR.b  
} 8=)A ksu  
C=%go1! $  
NjsP"  
public FileAccessI(String sName,long nPos) throws IOException B]Yj"LM)  
{ $T]1<3\G  
oSavedFile = new RandomAccessFile(sName,"rw"); -"!V&M  
this.nPos = nPos; #@lr$^M  
oSavedFile.seek(nPos); /KlA7MH6  
} R/<  /g=  
gh i!4  
*b7 HtUA  
public synchronized int write(byte[] b,int nStart,int nLen) hiU_r="*ox  
{ }wj*^>*  
int n = -1; >,hJ5-9  
try{ A 7DdUNR  
oSavedFile.write(b,nStart,nLen); EX8]i,s|E  
n = nLen; 5g/^wKhKG  
} *M- .Vor?R  
catch(IOException e) :M|bw{P*  
{ \+L_'*&8  
e.printStackTrace (); $`_(%tl  
} YVu8/D@ o  
gtjgC0   
a; /4 ht  
return n; _2f}WY3S  
} o)S>x0| [  
ecf<(Vl}  
j cx/ZR  
} >{Lfrc1  
fp12-Hk ~  
0Xk;X1Xl  
/* HzbO#)Id-I  
**SiteInfoBean.java s/Q}fW$ex  
*/ ,EwJg69  
package NetFox; ,ISq7*%F  
{} vl^b  
vbwEX6  
public class SiteInfoBean { 5:n&G[Md  
8Bhot,u'T  
t*.v!   
private String sSiteURL; //Site's URL PO)5L  
private String sFilePath; //Saved File's Path &\!-d%||)  
private String sFileName; //Saved File's Name {"{J*QH  
private int nSplitter; //Count of Splited Downloading File ax7 M  
Q&M(wnl5  
z:< (b   
public SiteInfoBean() ]p0m6}B  
{//nSplitter的缺省值为5 9iS3.LCfX  
//default value of nSplitter is 5 :Q\h'$C  
this("","","",5); \I'A:~b)L  
} Txoc  
UK& E#i  
=WDf [?ED  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) {-17;M $  
{ Z$WT ~V  
sSiteURL= sURL;  -U*XA  
sFilePath = sPath; $V5Ol6@ 2  
sFileName = sName; bdcuO)3  
this.nSplitter = nSpiltter; YrZAy5\  
n]8_]0{qi  
zh50]tX  
} G9V zVx#T#  
@uH7GW}$g  
Zjo9c{\  
public String getSSiteURL() UI;!_C_  
{ &V$'{  
return sSiteURL; SB  \ptF  
} k5}i^^.  
!uHI5k,f  
*r9I 1W  
public void setSSiteURL(String value) f#X`e'1  
{ [;I.aT}R!;  
sSiteURL = value; 2 ] 4R`[#  
} AvV.faa  
1 !\pwd@{  
`yC R.3+  
public String getSFilePath() 9"V27"s  
{ \t!+]v8f8  
return sFilePath; L<Lu;KnY6  
} _0vXujz  
Wa[~)A  
xX"?3%y>  
public void setSFilePath(String value) 8Q6il-  
{ 5#2vSq!H  
sFilePath = value; YHKm{A ]  
} {[Yv@CpN  
9:=a FP  
4AF" +L  
public String getSFileName() n+!.0d}6  
{ ~i  &K,  
return sFileName; 9Pem~<  
} z1V0WDVm  
|fzo$Bq  
0p[$8SCJ  
public void setSFileName(String value) {b#c0>.8-  
{ *dKA/.g  
sFileName = value; Tzk8y 7$[  
} }"cb^3  
C ]r$   
Z;n}*^U  
public int getNSplitter() g#70Sg*d  
{ Pq_Il9  
return nSplitter; kYR&t}jlCg  
} D#k>.)g  
^|sQkufo  
WQK#&r*  
public void setNSplitter(int nCount) |r /}r,t}  
{ PGw"\-F  
nSplitter = nCount; wCI.jGSBW  
} liU=5 BL  
} *y0`P0V|8  
|"@E"Za^  
Cu|n?Uk  
/* @:c 1+  
**Utility.java _5X}&>>lhF  
*/ 2ag]p  
package NetFox; ,-{j.  
T+~~w'v0  
cAiIbh>c  
public class Utility { JT:9"lmJz,  
}'Z(J)Bg  
=1esUO[nx  
public Utility() ^ #Wf  
{ GUcuD^Fe  
TVjY8L9'h  
{Qhv HV  
} V K NCK  
x[>A'.m@)  
//线程睡眠 g^]Q*EBa  
public static void sleep(int nSecond) q,*IR*B:a  
{ N.&K"J  
try{ |RpC0I  
Thread.sleep(nSecond); Xz5=fj&  
} c/hml4  
catch(Exception e) YqDw*S{  
{ /`'50C j  
e.printStackTrace (); L~yy;)]W  
} r[?rwc^  
} QOP*vH >J  
nTHP~]  
//日志 5Pr<%}[S^  
public static void log(String sMsg) &FK=w]P  
{ > PYe"  
System.err.println(sMsg); !?+3 jzG  
} dyx 4_!fO  
oS`F Yy  
> *_?^F_  
public static void log(int sMsg) JN8k x;@  
{ Bf-&[ 5N}  
System.err.println(sMsg); a1}W2;W0]g  
} qQom=x  
} "Srp/g]a  
2dq{n.cgs  
UGN. ]#"#  
/* PNKmI  
**TestMethod.java fe Q%L  
*/ B;-oa;m:E=  
package NetFox; Y0b.utR&  
mj,r@@k:=+  
L8$7^muad  
public class TestMethod { |fJ,+)_(  
UtWoSFZ'o!  
LD6fi  
public TestMethod() \(z)]D  
{ ///xx/weblogic60b2_win.exe \fKv+  
try{ g =%W"v  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I#,,h4C  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V]<dh|x  
SiteFileFetch fileFetch = new SiteFileFetch(bean); wHY;Y-(ZT  
fileFetch.start(); r|#4+'  
} FINM4<s)  
catch(Exception e){e.printStackTrace ();} pkT a^I  
I|PiZ1]2 Y  
#F9$"L1Hg  
} `hfwZ*s  
jt]+(sx  
FIS-xpv$  
public static void main(String[] args) `"bm Hs7  
{ O+e8}Tmm  
new TestMethod(); u ) ld  
} B]hZ4.B1  
} }W YY5L8^  
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