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http断点续传简单实现(java)

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/* fkE4 [X7f  
**SiteFileFetch.java #mg6F$E  
*/ >Ia{ZbQV  
package NetFox; gQaBQq9  
import java.io.*; c:etJ  
import java.net.*; nIdB,  
[tYly`F  
@igGfYy  
public class SiteFileFetch extends Thread { K3*8JF7_F  
hZ NS$  
q<(yNqMKP  
SiteInfoBean siteInfoBean = null; //文件信息Bean BwtjTwd  
long[] nStartPos; //开始位置 8 tMfh  
long[] nEndPos; //结束位置 !4-B xeNY\  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 1A\Jh3;Q  
long nFileLength; //文件长度 T0BFit6  
boolean bFirst = true; //是否第一次取文件 rlG& wX  
boolean bStop = false; //停止标志 ol]"r5#Q_H  
File tmpFile; //文件下载的临时信息 S^nshQI  
DataOutputStream output; //输出到文件的输出流 ,E,oz{,i(  
WE\@ArY>  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) I;iJa@HWQ  
public SiteFileFetch(SiteInfoBean bean) throws IOException :*|%g  
{ gyi<ot;  
siteInfoBean = bean; _kUf[&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); sYnf #'  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); ,ErJUv  
if(tmpFile.exists ()) F<SMU4]YdG  
{ 2q V.`d  
bFirst = false; >7%Gd-;l  
read_nPos(); F FHk0!3  
} MT{7I"  
else d]Y-^&]{]  
{ N&g9z{m7  
nStartPos = new long[bean.getNSplitter()]; mFCDwh]  
nEndPos = new long[bean.getNSplitter()]; EfA*w/y  
} 1haH2F^ q3  
Cv7FVl-I  
_  dFZR  
L3[r7 b  
} r #H(kJu,  
xb/L AlJ  
9W{`$30  
public void run() %|mRib|<C  
{ pzcV[E1  
//获得文件长度 QC@nRy8%  
//分割文件 -= {Z::}S"  
//实例FileSplitterFetch N"-</kzV  
//启动FileSplitterFetch线程 xXG-yh  
//等待子线程返回 E?%SOU<  
try{ 5!WQ  
if(bFirst) p H&Tb4  
{ 4o7(cP  
nFileLength = getFileSize(); TAfLC)  
if(nFileLength == -1) >y&Db  
{ gG"W~O)yv  
System.err.println("File Length is not known!"); E.*TJ  
} >E*j4gg  
else if(nFileLength == -2) TI '(  
{ E"LSM]^^<f  
System.err.println("File is not access!"); jSMvZJX3n  
} 8@`"ZzM  
else so[i"ZM)  
{ bb<qnB  
for(int i=0;i<nStartPos.length;i++) m1,?rqeb  
{ [UO?L2$&  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); 5I#L|+  
} fq*. 4s #  
for(int i=0;i<nEndPos.length-1;i++) l :sZ  
{ Q-<,+[/  
nEndPos = nStartPos[i+1]; w74 )kIi  
} {Rc!S? 8  
nEndPos[nEndPos.length-1] = nFileLength; AhjK*nJF  
} S3cjw9V  
} q ld2<W  
_TF\y@hF*D  
;dXQB>Za  
//启动子线程 c\2+f7o@  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `-)!4oJ]  
for(int i=0;i<nStartPos.length;i++) V6)e Jy  
{ kpc3l[.A  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Af8&PhyrU  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wc #+ Yh6  
nStartPos,nEndPos,i); 7:fC,2+  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~G0\57;h  
fileSplitterFetch.start(); ?m&?BsW$)  
} H|a9};pO\  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1.7tXjRd+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'FB?#C%U  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *=]hc@  
nEndPos = " + nFileLength); {XC1B  
// fileSplitterFetch[nPos.length-1].start(); U`gQ7  
JffjGf-o  
pk&kJ307  
//等待子线程结束 d*7nz=0&$  
//int count = 0; ~*-(_<FH  
//是否结束while循环 < C54cO  
boolean breakWhile = false; XA8{N  
>T*/[{L8;  
9qIdwDRY  
while(!bStop) fhx_v^< X  
{ 4k9O6  
write_nPos(); YGp8./ma<I  
Utility.sleep(500); r^3QDoy  
breakWhile = true; " 9=F/o9  
p|mt2oDjw  
Ap}^6_YXd  
for(int i=0;i<nStartPos.length;i++) ka_]s:>+  
{ m.ib#Y)y  
if(!fileSplitterFetch.bDownOver) _M n7zt1^  
{ u&)+~X  
breakWhile = false; rUC@Bf  
break; FJ}RT*7_C  
} `<I+(8]Uz  
} B+:'Ld](  
if(breakWhile)  /[f9Z:>V  
break; _c*0Rr  
?yKW^,q+  
Xo[={2_  
//count++; N?`-$C ]  
//if(count>4) fp^!?u  
// siteStop(); ;B[*f?y-  
} B%HG7  
3OUZR5_$  
lp`raN No  
System.err.println("文件下载结束!"); V+7x_>!&)  
} VEAf,{)Q  
catch(Exception e){e.printStackTrace ();} 96fzSZS,  
} #DMt<1#:  
HorFQ?8  
bYT,f.,5{  
//获得文件长度 NFT&\6!o  
public long getFileSize() -h&AO\*^W  
{ h WvQh  
int nFileLength = -1; (8C ,"Dc[0  
try{ <uXZ*E  
URL url = new URL(siteInfoBean.getSSiteURL()); [d="94Ab  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <uUHr,#  
httpConnection.setRequestProperty("User-Agent","NetFox"); H+&c=~D\_  
. IBy'  
Y#3<w  
int responseCode=httpConnection.getResponseCode(); 3DH} YAUU  
if(responseCode>=400) O)g\/uRy  
{ RJ/4T#b"+  
processErrorCode(responseCode); h$`P|#V&  
return -2; //-2 represent access is error s)HLFdis@  
} rt+%&% wt  
W0GDn  
d(u"^NH;  
String sHeader; $[5S M>e]  
m44Ab6gpsb  
29R_?HBH  
for(int i=1;;i++) (=n{LMa  
{ 2l5>>yY  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Y|WSKY*  
//Utility.log(in.readLine()); QXTl'.SfF  
sHeader=httpConnection.getHeaderFieldKey(i); d>j`|(\  
if(sHeader!=null) V=%j ]`Os  
{ 6?an._ C  
if(sHeader.equals("Content-Length")) #*QnO\.  
{ NRU&GCVwu  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [=dK%7v  
break; 9r,)Bw!RP  
} L4bx [  
} e nsou!l  
else CmyCne   
break; j9FG)0  
} y \M]\^[7  
} DEj6 ky  
catch(IOException e){e.printStackTrace ();} i,5mH$a&u:  
catch(Exception e){e.printStackTrace ();} '6Lw<#It  
]3B8D<p  
n o6q3<re  
Utility.log(nFileLength); p%;n4*b2  
hfUN~89;  
{G _ :#cep  
return nFileLength; oC"1{ybyl  
} 'Em5AA`>  
QahM)Gb  
rVo0H.+N)`  
//保存下载信息(文件指针位置) H{ Fww4pn  
private void write_nPos() K"lZwU\:On  
{ $9LI v  
try{ "Dr8}g:X  
output = new DataOutputStream(new FileOutputStream(tmpFile)); W!@*3U]2R  
output.writeInt(nStartPos.length); L[M`LZpJo  
for(int i=0;i<nStartPos.length;i++) }@R*U0*E  
{ 9fLxp$`(T  
// output.writeLong(nPos); z=YHRS  
output.writeLong(fileSplitterFetch.nStartPos); $CT 2E  
output.writeLong(fileSplitterFetch.nEndPos); /r Q4JoR>  
} AXK6AZjX  
output.close(); y2nwDw(xF  
} IEbk_-h[  
catch(IOException e){e.printStackTrace ();} puE!7 :X7  
catch(Exception e){e.printStackTrace ();} nQy%av$  
} QzV Q}  
?H7YmN  
9Tju+KcK  
//读取保存的下载信息(文件指针位置) =\[}@Kh  
private void read_nPos() 2h:*lV^  
{ Vifh`BSP  
try{ S.^/Cl;aj  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j>D[iHrH  
int nCount = input.readInt(); gHL v zm  
nStartPos = new long[nCount]; )HaW# ,XB  
nEndPos = new long[nCount]; ~Vh< mt  
for(int i=0;i<nStartPos.length;i++) 'aLTiF+  
{ ^p@ #  
nStartPos = input.readLong(); 57nSyd] PR  
nEndPos = input.readLong(); (fSpY\JPI  
} .=I:cniw\r  
input.close(); 71)DLGL  
} AEUXdMo  
catch(IOException e){e.printStackTrace ();} 5!tiu4LU  
catch(Exception e){e.printStackTrace ();} -chk\75  
} p`oSI}ZwB  
A9:dHOmT^U  
)p?p39>h  
private void processErrorCode(int nErrorCode) RxeyMNd  
{ J ~"h&>T  
System.err.println("Error Code : " + nErrorCode); PPj_NV  
} p|q}z/  
Uo D@ix&0  
pb`!_GmB  
//停止文件下载 f&ZFG>)6  
public void siteStop() Oo-%;l`&  
{ 7ThGF  
bStop = true; cz{5-;$9Z  
for(int i=0;i<nStartPos.length;i++) [H-r0Ah  
fileSplitterFetch.splitterStop(); h#EksX  
=~|:93]k  
n"Gow/-;  
} O /S:S  
} :<"b"{X"  
//负责部分文件的抓取 x{|`q9V~ N  
**FileSplitterFetch.java v c r5  
*/ M@ TXzn!&o  
package NetFox; S*0P[R  
<"}Gvi  
dI$U{;t  
import java.io.*; "{1SDbwmMo  
import java.net.*; S8S<>W  
Q,AM<\S  
SniKC qmC]  
public class FileSplitterFetch extends Thread { ^ y1P~4w?  
jdEqa$CXG  
|1rKGDc  
String sURL; //File URL [0lu&ak[&  
long nStartPos; //File Snippet Start Position z}gfH|  
long nEndPos; //File Snippet End Position )9PP3"I  
int nThreadID; //Thread's ID r/G6O  
boolean bDownOver = false; //Downing is over p,cw- lN  
boolean bStop = false; //Stop identical }BR@vY'd  
FileAccessI fileAccessI = null; //File Access interface |cBeyqr  
mqIcc'6f  
'9w.~@7  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i^O(JC  
{ (mvzGXNz4  
this.sURL = sURL; P p]Ygt'u  
this.nStartPos = nStart; doj$chy  
this.nEndPos = nEnd; .&Q'aOg  
nThreadID = id; _$f XK  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {,Py%.vvR  
} >&`S$1 o  
U`-]U2 "  
ivi,/~L  
public void run() 7^3a296  
{ tt%lDr1A)  
while(nStartPos < nEndPos && !bStop) a-9Y &#U  
{ 2rG;j52))a  
]-7$wVQ<  
7YLG<G!v)]  
try{ 4|EV`t}EV  
URL url = new URL(sURL); "T?hIX/p _  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vw P+tM  
httpConnection.setRequestProperty("User-Agent","NetFox"); qa!3lb_'M  
String sProperty = "bytes="+nStartPos+"-";  HuCzXl  
httpConnection.setRequestProperty("RANGE",sProperty); P_:~!+W,  
Utility.log(sProperty); O:hCUr  
jH4'jB  
;n"Nv }<C  
InputStream input = httpConnection.getInputStream(); EU0b>2n4  
//logResponseHead(httpConnection); 7E}.P1  
QUSyVp{$  
W-ctx"9DS  
byte[] b = new byte[1024]; Y#A0ud,  
int nRead; ;hcOD4or  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o2J-&   
{ ='p&T|&  
nStartPos += fileAccessI.write(b,0,nRead); At?]FjL6S  
//if(nThreadID == 1) FK2* O  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^#Ruw?D  
} gFx2\QV  
R54wNm @  
GIyb0XjTw  
Utility.log("Thread " + nThreadID + " is over!"); /%P|<[< [  
bDownOver = true; [RqL0EP  
//nPos = fileAccessI.write (b,0,nRead); e=yQFzQT)  
} h>A~..  
catch(Exception e){e.printStackTrace ();} Q`Z=}^  
} 3a_=e B  
} f=f8) +5  
tt=JvI9>  
X,Q'Xe /  
//打印回应的头信息 m,TN%*U!  
public void logResponseHead(HttpURLConnection con) 2A5R3x= \  
{ Ac'0  
for(int i=1;;i++) Q=+*OQV29  
{ YH 5jvvOI  
String header=con.getHeaderFieldKey(i); .h0@Vs  
if(header!=null) oQ=v:P]  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aT[qJbp1  
Utility.log(header+" : "+con.getHeaderField(header)); &:3uK`  
else t04_~e  
break; tcm?qro)  
} R'#1|eWCa  
} 5Wyo!pRi  
hS?pc<~`#  
LxcC5/@\~(  
public void splitterStop() 3/j^Ao\fw  
{ PqhR^re0.  
bStop = true; &T i:IC%M  
} AxsTB9/  
~eVq Fc  
\9Z1'W  
} l[_ y|W5  
K ]  
5vfzSJ  
/* WPN4mEow  
**FileAccess.java ~o+:M0)}  
*//文件访问(定位,写) {`Jr$*;  
package NetFox; uVQH,NA,  
import java.io.*; n[mVwQ(%  
#DqVh!t"  
.w.jT"uD!  
public class FileAccessI implements Serializable{ tJ_6dH8Y  
'1jG?D  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *i=+["A  
RandomAccessFile oSavedFile; 0# )I :5  
long nPos; [b=l'e/  
3Y L  
Ub(8ko:8$  
public FileAccessI() throws IOException /|)VO?*D  
{ B*zR/?U^  
this("",0); $wQkTx  
} JFJ_ PphvD  
"RkbT O  
4GiHp7Y&A  
public FileAccessI(String sName,long nPos) throws IOException 5q.d$K |  
{ {DI`HB[  
oSavedFile = new RandomAccessFile(sName,"rw"); 6<uJ}3  
this.nPos = nPos; ^h c&rD)_  
oSavedFile.seek(nPos); Ny\c>$z  
} BotGPk><c  
fpDx)lQ  
sW53g$`v  
public synchronized int write(byte[] b,int nStart,int nLen) /YyimG7  
{ &sbKN[xM  
int n = -1; w;=fi}<G|e  
try{ WeqE 9@V  
oSavedFile.write(b,nStart,nLen); e]1&f.K  
n = nLen; ,vxxp]#5  
} n%SR5+N"  
catch(IOException e) fku\O<1  
{ j[^(<R8  
e.printStackTrace (); d>RoH]K4  
} ed=pRb  
c Nhy.Z~D  
go6XUe  
return n; c7E|GZ2Hc  
} pd3=^ Zi  
#[Z1W8e  
\~LwlOo%R  
} !4"!PrZDB  
vxey $Ir  
e%Sw(=a  
/* oCCTRLb02  
**SiteInfoBean.java JlM0]__v  
*/ 5-=&4R\k  
package NetFox; 4TP AD)C  
p)dD{+"/2  
ja<!_^h=At  
public class SiteInfoBean { b3h3$kIYN  
h^H~q<R[T  
lBYc(cr  
private String sSiteURL; //Site's URL mMz^I7$  
private String sFilePath; //Saved File's Path F+c4v A})  
private String sFileName; //Saved File's Name $X>$)U'p&-  
private int nSplitter; //Count of Splited Downloading File 8zOoVO  
>Q`\|m}x)Q  
BE#s@-zR=p  
public SiteInfoBean() O/?Lk*r  
{//nSplitter的缺省值为5 d,hKy2  
//default value of nSplitter is 5 U= Gw(  
this("","","",5); cC NyW2'  
} VssD  
T3JM8  
VV$$t;R/  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #835 $vOe  
{ /OX;3" +1  
sSiteURL= sURL; #Yqj27&  
sFilePath = sPath; ^#V7\;v$G  
sFileName = sName; "B$r{ vG  
this.nSplitter = nSpiltter; *(?tf{  
]1^F  
THOXs; k0  
} MnQ4,+ji-  
w@jC#E\  
0bcbH9) 1q  
public String getSSiteURL() ik;S!S\v  
{ BDO]-y  
return sSiteURL; Qw,{"J  
} iB1+4wa  
S5,y!K]C~  
.?Pghqq.  
public void setSSiteURL(String value) [yEH!7  
{ )R- e^Cb  
sSiteURL = value; ac2G;}B|  
} 8F;r$i2  
]y **ZFA  
Yu`KHvur  
public String getSFilePath() ]46-TuH  
{ /`2t$71)  
return sFilePath; G]$.bq[v  
} FUD M]:XQ  
1p|h\H  
&|LP>'H;  
public void setSFilePath(String value) J/{!_M-  
{ u> @ Yoyc  
sFilePath = value; PlX6,3F  
} z5UY0>+VdS  
1Fs:&*=  
hb,G'IU  
public String getSFileName() Mqk[+n  
{ c:@lR/oe"  
return sFileName; Y~fa=R{W  
} i:@n6GW+iw  
:mI[fQ  
|_H{ B+.  
public void setSFileName(String value) jkrv2 `"  
{ b14WIgjsl  
sFileName = value; "L)=Y7Dx  
} .Jvy0B} B  
,5 A&  
#% 1|$V*:  
public int getNSplitter() (pud`@D;[  
{ f-'$tMs  
return nSplitter; Tg-HR8}X  
} T l%n|pc  
br[n5  
1k:s~m?!  
public void setNSplitter(int nCount) DH*=IzcJf  
{ X  *f le  
nSplitter = nCount; /BaXWrd+  
} $&@etsW0/  
} "+BNas^rF  
Ev)aXP  
8A,="YIt  
/* ;/- X;!a>  
**Utility.java ~Bi{k'A9  
*/ b~L8m4L  
package NetFox; C>0='@LB@r  
L>PPAI  
wvu h   
public class Utility { yrgb6)]nm@  
OM1pyt  
)`V__^  
public Utility() M?FbBJ`sF  
{ !J%m7 A  
AY~~a)V  
/`x)B(b  
} [-pB}1Dxb  
M%#H>X\/  
//线程睡眠 xdV $dDCT  
public static void sleep(int nSecond) Q&;d7A.@  
{ ]di9dLT  
try{ (d@ =   
Thread.sleep(nSecond); ` g5S  
} h=`1sfz  
catch(Exception e) I8]q~Q<-P  
{ M,f|.p{,Y  
e.printStackTrace (); %J 'RO  
} Z"u|-RoBV  
} "p[FFg  
#]_S)_Z-  
//日志 H5 'Le{  
public static void log(String sMsg) Z?o?"|o  
{ .}6Mj]7?i  
System.err.println(sMsg); jh*aD=y  
} &8^1:CcE  
iI.d8}A  
{k#RWDespy  
public static void log(int sMsg) 5uJ{#Zd  
{ ?{bAyh/  
System.err.println(sMsg); Q x]zz4jD  
} .^} vDA  
} u3XQ<N{Gj  
`Y5{opG7-  
mEM/}]2  
/* `=B0NC.3  
**TestMethod.java }s7ibm'  
*/ |##rs  
package NetFox; C*f3PB=H_  
8pQ:B/3=  
F~Z~OqCS  
public class TestMethod { 5{@Hpj/B  
\a|bx4M  
df$VC  
public TestMethod() U $ bLt  
{ ///xx/weblogic60b2_win.exe ~_YU%y  
try{ \;%DDw  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); IRxFcLk  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Wxxnc#;lv  
SiteFileFetch fileFetch = new SiteFileFetch(bean); tHj |_t  
fileFetch.start(); \1p_6U7  
} @A-^~LoP.  
catch(Exception e){e.printStackTrace ();} dLtn,qCX0^  
|4XR [eX  
BW61WH?  
} )ZI9n7  
f/&k $,w  
0qV"R7TW  
public static void main(String[] args) h{sY5d'D  
{ xzRs;AXOp  
new TestMethod(); _%`<V!RT\  
} rLfhm Ds%u  
} Yom,{;Bv  
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