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http断点续传简单实现(java)

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/* OVwcjhQ  
**SiteFileFetch.java Mnj\t3:  
*/ 9|kc$+(+6  
package NetFox; V*xo3hU  
import java.io.*; Hz?C9q3BX  
import java.net.*; \<cs:C\h7  
v[k;R  
OvL@@SX |  
public class SiteFileFetch extends Thread { 9'1XZpM1  
VFmG\  
u'Od~x^z  
SiteInfoBean siteInfoBean = null; //文件信息Bean |6]2XW  
long[] nStartPos; //开始位置 _/FpmnaY  
long[] nEndPos; //结束位置 z|KQiLza  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 T\ixS-%^  
long nFileLength; //文件长度 XH^X4W  
boolean bFirst = true; //是否第一次取文件 47S1mxur  
boolean bStop = false; //停止标志 EC`!&Yp+  
File tmpFile; //文件下载的临时信息 r;>2L'  
DataOutputStream output; //输出到文件的输出流 xIOYwVC  
rM?O2n  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) :6}Zo  
public SiteFileFetch(SiteInfoBean bean) throws IOException Q9Tt3h2ga  
{ 0m3:!#\  
siteInfoBean = bean; mP!=&u fcU  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); kGz0`8U Ru  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); s5`CV$bz  
if(tmpFile.exists ()) !hMD>B2Z  
{ eo#2n8I>=1  
bFirst = false; a ~  
read_nPos(); !?AgAsSmc  
} U?@ s`.  
else 5|nT5oS  
{ 4q9+a7@  
nStartPos = new long[bean.getNSplitter()]; Yz%AKp  
nEndPos = new long[bean.getNSplitter()]; c0 I;8z`b  
} %S`ygc}|  
e8Ul^]  
U z*7J  
MNuBZnO  
} EgE% NY~  
I{/}pr>  
3np |\i  
public void run() n]%T>\gw  
{ 5`_UIYcI  
//获得文件长度 '' Pu  
//分割文件 9$ VudE>;  
//实例FileSplitterFetch TnuaP'xZ  
//启动FileSplitterFetch线程 g!QX#_~Il  
//等待子线程返回 2|6E{o  
try{ `>HM<Nn-0  
if(bFirst) @IXvp3r  
{ "dkDT7  
nFileLength = getFileSize(); ;7:_:o[.  
if(nFileLength == -1) !~j-5+DI  
{ \GF 9;N}V  
System.err.println("File Length is not known!"); E Pd9'9S  
} )ajF ca@v  
else if(nFileLength == -2) h!~Qyb>W  
{ k<Y}BvAYB  
System.err.println("File is not access!"); _?}[7K!~d  
} R!+_mPb=Q*  
else -XJXl}M.  
{ a< E\9DL  
for(int i=0;i<nStartPos.length;i++) Qhc>,v)  
{ Ii.0Bul  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); OMY^'g%w  
} &UFj U%Z%  
for(int i=0;i<nEndPos.length-1;i++) =q\Ghqj1  
{ r(ZMZ^  
nEndPos = nStartPos[i+1]; Ye=c;0V(w  
} ?hFG+`"W  
nEndPos[nEndPos.length-1] = nFileLength; >s%&t[r6  
} 6_=t~9sY  
} B4#XQ-  
P&sn IJ  
ov 'g'1}  
//启动子线程 >h Rq  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; t}Q PPp y  
for(int i=0;i<nStartPos.length;i++) X/8TRiTFv  
{ 2Wx~+@1y  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(),  Qi;62M  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), K,f"Q<sU%  
nStartPos,nEndPos,i); mNQ~9OJ1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nb30<h  
fileSplitterFetch.start(); 0en Bq>vr  
} _xmS$z)TO  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {qJ(55  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x:? EL)(  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pba`FC4R  
nEndPos = " + nFileLength); IaHu$` v  
// fileSplitterFetch[nPos.length-1].start(); ` it<\r[=  
>zS<1  
o>l/*i0I  
//等待子线程结束 rw }wQP_'  
//int count = 0; Zl\$9Q_  
//是否结束while循环 -;Ij ,  
boolean breakWhile = false; q; ?Kmk  
,]LsX"u  
L; o$vI~U,  
while(!bStop) 1$S`>M%a  
{ 2v\<MrL  
write_nPos(); H/^t]bg,  
Utility.sleep(500); sK/Z 'h{|  
breakWhile = true; @Rw]boC  
yEPkF0?  
t%fcp  
for(int i=0;i<nStartPos.length;i++) (7*((  
{ B.#.gB#C  
if(!fileSplitterFetch.bDownOver) eJy}W /  
{ >4G~01  
breakWhile = false; Q3'L\_1L  
break; <HfmNhI85(  
} <-(n48  
} \sEH)$R'  
if(breakWhile) >mW*K _~  
break; h|{DIG3  
CeINODcT  
o:c:hSV  
//count++; nr?|!gj  
//if(count>4) m85H x1!p.  
// siteStop(); ~vscATQ  
} 0..]c-V(G  
3Hi[Y[O`%P  
IIY3/   
System.err.println("文件下载结束!"); |@Ze{\  
} z5 g4+y,  
catch(Exception e){e.printStackTrace ();} ] L6LB \  
} nc9sfH3  
<3fY,qw  
9#:B_?e=  
//获得文件长度 5_+pgJL  
public long getFileSize() L(q~%  
{ Ve[[J"ze  
int nFileLength = -1; 43s8a  
try{ )ZMR4U$+v  
URL url = new URL(siteInfoBean.getSSiteURL()); 9CFh'>}$  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :;URLl0  
httpConnection.setRequestProperty("User-Agent","NetFox"); Zv5vYe9Ow  
XR+  
zrL+:/t  
int responseCode=httpConnection.getResponseCode(); q^ eLbivVE  
if(responseCode>=400) nC5]IYL|  
{ VLcwBdo  
processErrorCode(responseCode); ly::?  
return -2; //-2 represent access is error 6=p!`DOd  
} h'"~t#r  
hH~GH'dnaE  
62 9g_P)  
String sHeader; (b"kN(  
=Bos>;dl  
7{Zs"d{s  
for(int i=1;;i++) !7n`-#)  
{ 5BS !6o;P'  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); rAZ~R PrW  
//Utility.log(in.readLine()); 4G'-"u^g  
sHeader=httpConnection.getHeaderFieldKey(i); z#GrwE,r   
if(sHeader!=null) =h\uC).t&  
{ yqKSaPRA  
if(sHeader.equals("Content-Length")) ziXI$B4-  
{ 6 2LLfD  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Vtv1{/@+c  
break; OjurfVw  
} .s%dP.P:i1  
} i$6o>V6  
else 8<=]4-X@  
break; IqCh4y3  
} ]2rC n};  
} $ qTv2)W1{  
catch(IOException e){e.printStackTrace ();} ,*Z/3at}5M  
catch(Exception e){e.printStackTrace ();} d Z}|G-:  
4l@aga  
JOo+RA5d  
Utility.log(nFileLength); OU[ FiW-E  
|& _(I  
 tPChVnB  
return nFileLength; P-\65]`C  
} 3'!*/UnU  
IweNe`Z  
vu~7Z;y(<j  
//保存下载信息(文件指针位置) ot,=.%O  
private void write_nPos() 'DD~xCXE  
{ eQJyO9$G  
try{ \u*[mrX_B:  
output = new DataOutputStream(new FileOutputStream(tmpFile)); T'-kG"lb  
output.writeInt(nStartPos.length); D22A)0+_  
for(int i=0;i<nStartPos.length;i++) NEt_UcC  
{ W?yGV{#V(=  
// output.writeLong(nPos); AWDy_11Nm  
output.writeLong(fileSplitterFetch.nStartPos); vlo!D9zsV3  
output.writeLong(fileSplitterFetch.nEndPos); ]<k+a-Tt  
} "4L_BJZ  
output.close(); y3ST0=>j}  
} ) ):w`^6  
catch(IOException e){e.printStackTrace ();} ({mlA`d]  
catch(Exception e){e.printStackTrace ();} NY/-9W5T4  
} Uy<n7*H  
0RHjA& r3v  
>AW&Lfw$  
//读取保存的下载信息(文件指针位置) )v %tyU  
private void read_nPos() 11B8 LX  
{  g^))  
try{ `V{'GF&[  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /%AA\`: 6  
int nCount = input.readInt(); "QmlW2ysi  
nStartPos = new long[nCount]; f@ .s(i=z  
nEndPos = new long[nCount]; =D Tbz3<  
for(int i=0;i<nStartPos.length;i++) &%4A3.qE  
{ 2+|U!X  
nStartPos = input.readLong(); x{3q'2  
nEndPos = input.readLong(); IZ@M K  
} sOm&7A?  
input.close(); {j%7/T{  
} o`.5NUn  
catch(IOException e){e.printStackTrace ();} %$F_oO7"  
catch(Exception e){e.printStackTrace ();} X<d`!,bn@  
}  #zg"E<  
(H-kWT  
BOme`0A  
private void processErrorCode(int nErrorCode) 3-gy)5.x e  
{ SHQgI<D7  
System.err.println("Error Code : " + nErrorCode); z q@"qnr  
} 9`Xr7gmQf  
GriFb]ml"  
%JuT'7VB  
//停止文件下载 W];l[D<S*  
public void siteStop() o)M<^b3KO  
{ Wb;D9Z  
bStop = true; =QhK|C!$A  
for(int i=0;i<nStartPos.length;i++) V82hk0*j  
fileSplitterFetch.splitterStop(); (/C 8\}Ox  
AQ)J|i  
 k<  
} ' BY|7j~  
} Q+dLWFI  
//负责部分文件的抓取 AdWP  
**FileSplitterFetch.java Is>~P*2Y=  
*/ U,V+qnS  
package NetFox; ;rC< C  
$ spk.j  
Wux[h8G  
import java.io.*; _CG ED{b@  
import java.net.*; C /w]B[H  
c"pu"t@/Z  
gb/<(I )  
public class FileSplitterFetch extends Thread { _*n 4W^8  
k; ned  
#NWS)^&1b  
String sURL; //File URL qsdgG1<  
long nStartPos; //File Snippet Start Position |)%;B%  
long nEndPos; //File Snippet End Position V(0V$&qipc  
int nThreadID; //Thread's ID N^zFKDJG  
boolean bDownOver = false; //Downing is over TH*}Ja^/  
boolean bStop = false; //Stop identical vvF]g.,  
FileAccessI fileAccessI = null; //File Access interface lMe+.P|  
{GG;/Ns{f-  
]\*_}  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SzyaVBD3  
{ VJgYXPE `  
this.sURL = sURL; ?D=C8EX  
this.nStartPos = nStart; #pk  
this.nEndPos = nEnd; @k\npFKQm  
nThreadID = id; U&gI_z[  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r tH #j  
} ^AC2  zC  
,YF1* 69  
.DHQJ|J-1  
public void run() cg^=F_h  
{ 3+H[S#e:Z  
while(nStartPos < nEndPos && !bStop) @j=rS S  
{ n"f: 6|<  
j>#ywh*A  
9S8V`aC  
try{ vAfYONU  
URL url = new URL(sURL); nTr{ D&JS  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;8yEhar  
httpConnection.setRequestProperty("User-Agent","NetFox"); FMz>p1s|dK  
String sProperty = "bytes="+nStartPos+"-"; abg` : E  
httpConnection.setRequestProperty("RANGE",sProperty); *@g>~q{`  
Utility.log(sProperty); Gq{);fq  
l]S%k&  
HH|N~pBJB  
InputStream input = httpConnection.getInputStream(); |};-.}u^`h  
//logResponseHead(httpConnection); &[_D'jm+S0  
bOD] `*q  
hZ-?-F?*@  
byte[] b = new byte[1024]; sU"sd7#A  
int nRead; ~$m:j];  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) l{hO"fzy  
{ ISg-?h/  
nStartPos += fileAccessI.write(b,0,nRead); 'L C0hoV  
//if(nThreadID == 1) kn}bb*eZ  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); f s2}a  
} VUzRA"DP|  
\2M{R  
N$M:&m3^  
Utility.log("Thread " + nThreadID + " is over!"); /]9(InM9/  
bDownOver = true; rtz  ]PH  
//nPos = fileAccessI.write (b,0,nRead); rbI 7 3'  
} t]8nRZ1  
catch(Exception e){e.printStackTrace ();} ,ygDNF  
} wLy:S.r  
} ];\XA;aOl}  
=" pNE#  
.GIygU_  
//打印回应的头信息 co{i~['u  
public void logResponseHead(HttpURLConnection con) op61-:q/  
{ 6yd?xeD  
for(int i=1;;i++) vPD%5 AJN  
{ `+@r0:G&v  
String header=con.getHeaderFieldKey(i); - @tL]]  
if(header!=null) -lb%X 3`  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U+:Mu]97  
Utility.log(header+" : "+con.getHeaderField(header)); [E9)Da_)i  
else JN3&(t  
break; Gp2C wyv  
} NGmXF_kqN  
} o':K4r;  
s,-}}6WO  
B]:?4Ov  
public void splitterStop() 7E;`1lh7  
{ vGchKN~_  
bStop = true; lf_q6y  
} p_CCKU  
(Ji=fh+  
SyI i*dH  
} Nh1, w  
*kt%.wPJ  
fr8hT(,s)  
/* T*92o:^  
**FileAccess.java O}X@QG2_  
*//文件访问(定位,写) cpM]APF-  
package NetFox; aMaqlqf  
import java.io.*; U3t) yr h  
SbH} cu8  
o^Qy71Uj  
public class FileAccessI implements Serializable{ '25zb+ -  
<=@6UPsn2  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Xw&vi\*m  
RandomAccessFile oSavedFile; QsyM[;\j:  
long nPos; m.c2y6<=  
X)S4vqf}  
Kc+TcC  
public FileAccessI() throws IOException :a_MT  
{ C^*}*hYk$  
this("",0); -+kTw06_C  
} @-.Tgpe@a  
;R^=($X  
_g6H&no[  
public FileAccessI(String sName,long nPos) throws IOException i7\MVI 8  
{ ;TboS-Y  
oSavedFile = new RandomAccessFile(sName,"rw"); 56H~MnX  
this.nPos = nPos; oWBjPsQ  
oSavedFile.seek(nPos); 0r]-Ltvl?}  
} ?6 "B4%7b  
na3lbwq  
Ie4X k  
public synchronized int write(byte[] b,int nStart,int nLen) bDnT><eH  
{ Wo6C0Z3g}  
int n = -1; I|_U|H!`  
try{ h&z(;B!;y.  
oSavedFile.write(b,nStart,nLen); ;Ngu(es6  
n = nLen; L<p.2[3  
} >z k6{kC  
catch(IOException e) wPaMYxO/  
{ DlQ*'PX7  
e.printStackTrace (); ]wEFm;N  
} s(y=u>  
Gg6<4T1  
CW?R7A/  
return n; -"}nm!j /5  
} mw~$;64;a  
8jz7t:0  
/<CgSW}  
} lLN5***47J  
[y(<1]i-a  
T)MZ`dM  
/* E|x t\ *  
**SiteInfoBean.java FH7l6b,^  
*/ lD,;xuQ  
package NetFox; TCK<IZKLqK  
3($tD*!o  
]~\%ANoi  
public class SiteInfoBean { _p0G8  
3mT6HGSKR  
1=mb2A  
private String sSiteURL; //Site's URL p s_o:*$l  
private String sFilePath; //Saved File's Path 7:n OAN}%  
private String sFileName; //Saved File's Name #Wely~  
private int nSplitter; //Count of Splited Downloading File D}nIF7r2N  
"(vm0@8><  
CMU\DO  
public SiteInfoBean() j "e]Ui  
{//nSplitter的缺省值为5 JF(&+\i<p  
//default value of nSplitter is 5 #=czqZw  
this("","","",5); -"d&Ow7o  
} -x+K#T0Z  
d ZxrIWx  
MR.c?P?0Q  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) R'h.lX  
{ 0> U7]wZKc  
sSiteURL= sURL; (`&E^t  
sFilePath = sPath; C@rIyBj1g  
sFileName = sName; 7? qRz  
this.nSplitter = nSpiltter; kw5`KfG9  
imZ"4HnPP  
u9G  
} uex([;y  
jGtu>|Gj  
&'W ~~ir  
public String getSSiteURL() Rz=wInFs  
{ \  6 : 7  
return sSiteURL; <MgC7S2I  
} AO]1`b:  
\Z$MH`_nu  
rWN%Tai-  
public void setSSiteURL(String value) Wrs6t  
{ 4[ =C,5r  
sSiteURL = value; O.$OLK;v  
} sQ8kLS_q8  
KvtJ tql;  
qw}. QwPT  
public String getSFilePath() -5MQ/ujQ  
{ U&u~i 3  
return sFilePath; YI+o:fGC5  
} DQ%(X&k  
|/~ISB  
<E\vc6n  
public void setSFilePath(String value) :zsMkdU  
{ {i/7Nx  
sFilePath = value; !'8jy_<9  
} fU ^5Dl  
7 MG<!U  
jF|LPWl  
public String getSFileName() !X+}W[Ic^  
{ yIqRSqM  
return sFileName; _t@9WA;+\  
} aHBM9%gV  
YAYwrKt  
c->?'h23)  
public void setSFileName(String value) Y&1Yc)*O  
{ p9j2jb,qy  
sFileName = value; bipA{VU  
} |jyD@Q,4  
xH{V.n&v  
7!^Zsp^+  
public int getNSplitter() KBwY _  
{ #s|,o Im  
return nSplitter; z_A34@a  
} `k~w 14~w  
?/^{sW' |  
ad`=A V]  
public void setNSplitter(int nCount) Jek3K&  
{ |#x]/AXa0/  
nSplitter = nCount; F7U$ 7(I2G  
} HC(o;,spO  
} ?<D1] Xv  
Zl{ DqC^  
b%|6y  
/* Pt?d+aBtV  
**Utility.java :0(:}V3z\  
*/ dyuT-.2  
package NetFox; vz`r !xj)  
n-:n.JX  
!sav~dB)  
public class Utility { `;z;=A*  
Cp^%;(@  
og8"#%  
public Utility() ^LAdN8Cbb  
{ <k 7q 9"\4  
n /Dk~Q)  
xoNn'LF#u  
} XMm (D!6  
KAm$^N5  
//线程睡眠 A?Gk8  
public static void sleep(int nSecond) :1e'22[=.  
{ JbW!V Y  
try{ - xQJY)  
Thread.sleep(nSecond); uU#e54^  
} e7JZk6GP#9  
catch(Exception e) 6cbIs_ g  
{ CB>O%m[1  
e.printStackTrace (); i`" L?3T  
} t$5)6zG  
} c4xXsUBQk  
LJ mRa  
//日志 FHbw &  
public static void log(String sMsg) ~{BR~\D  
{ 6 +x>g  
System.err.println(sMsg); 5.FAuzz  
} !-Md+I_  
t7b\#o  
lr&O@ 5"oy  
public static void log(int sMsg) rklK=W z  
{ h|Udw3N1L  
System.err.println(sMsg); #dm"!I>g  
} DF~{i{  
} `KzNBH,W  
lO5*n|Ic,  
D-4\AzIb  
/* Vh;P,no#  
**TestMethod.java ">NPp\t>/Z  
*/ + hKH\]  
package NetFox; l?swW+ x\  
O5?3 nYHa  
!:w&eFC6  
public class TestMethod { PR*qyELu  
_4MT,kN  
:h60  
public TestMethod() |4A938'4j  
{ ///xx/weblogic60b2_win.exe ck\gazo~q  
try{ Yeb-u+23  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ik Pm,ZN  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8f{;oO  
SiteFileFetch fileFetch = new SiteFileFetch(bean); \' ;zD-MX  
fileFetch.start(); GJIM^  
} 0I \l_St@  
catch(Exception e){e.printStackTrace ();} TNK~ETE4  
o? {rPFR  
pxi/ ]6pw  
} E HY}gG)  
5Bog\mS  
r-k,4Yz  
public static void main(String[] args) XH{P@2~l  
{ DqTp*hI  
new TestMethod(); nPo YjQi  
} E< Ini'od[  
} &Eqa y'  
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