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http断点续传简单实现(java)

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/* "`6n6r42  
**SiteFileFetch.java j5@:a  
*/ mo~*C   
package NetFox;  +H$!a  
import java.io.*; =IAsH85Q  
import java.net.*; qY 4#V k  
$=?@*p  
Ts~L:3oaQ  
public class SiteFileFetch extends Thread { $ cj>2.   
};'\~g,1  
nC{%quwh{  
SiteInfoBean siteInfoBean = null; //文件信息Bean xq"Jy=4Q*  
long[] nStartPos; //开始位置 #97h6m?  
long[] nEndPos; //结束位置 u.rY#cS,-R  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 wf1lyS  
long nFileLength; //文件长度 |p$spQ  
boolean bFirst = true; //是否第一次取文件 ePIiF_X  
boolean bStop = false; //停止标志 1>L(ul(qGF  
File tmpFile; //文件下载的临时信息 4Vq%N  
DataOutputStream output; //输出到文件的输出流 ,^icPQSwc  
6"dD2WV/  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类)  @3kKJ  
public SiteFileFetch(SiteInfoBean bean) throws IOException V`@>MOw^d  
{ $['Bv  
siteInfoBean = bean;  <T[E=#  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); F[ewn/]n  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); %/updw#{B  
if(tmpFile.exists ()) OT&k.!=  
{ Y2'cs~~$Ce  
bFirst = false; Ali9pvE  
read_nPos(); y!]CJigpZ  
} imiR/V>N  
else 7 I>G{  
{ ^] kF{ o?  
nStartPos = new long[bean.getNSplitter()]; WOh|U4vt  
nEndPos = new long[bean.getNSplitter()]; i*CZV|t US  
} ?.Pg\ur  
]r_;dYa  
aM4k *|H?  
z2Z^~, i  
} 7=(Hy\Q5xH  
a'\o 7_  
Mfv1Os:ST  
public void run() t|m=J`a{q;  
{ q{+_ <2U|  
//获得文件长度 10H)^p%3+  
//分割文件 {/pm<k=  
//实例FileSplitterFetch ;NRF=d>  
//启动FileSplitterFetch线程 d|4}obCt  
//等待子线程返回 `O'`eY1f  
try{ 3MRc 4UlB  
if(bFirst) Y3O#Q)-j$  
{ -kbg\,PW  
nFileLength = getFileSize(); %w7]@VZ  
if(nFileLength == -1) /a6Xa&(B  
{ UT="2*3gz  
System.err.println("File Length is not known!"); S]E.KLR?[;  
} ur$l Z0  
else if(nFileLength == -2) [|l?2j\  
{ yV^s,P1  
System.err.println("File is not access!"); t'ZWc\  
} )aX,%yK  
else S6[v;{xJ  
{ >|;aIa@9  
for(int i=0;i<nStartPos.length;i++) MeUaTJFEB  
{ ?mlNL/:  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); xC tmXo  
} E }ZJ)V7  
for(int i=0;i<nEndPos.length-1;i++) 0:b2(^]bg  
{ RVeEkv[qp  
nEndPos = nStartPos[i+1]; _/O25% l  
} Ge<nxl<Bd  
nEndPos[nEndPos.length-1] = nFileLength; @]ao"ui@/  
} : "1XPr  
} a+Ac[>  
wgw(YU  
'R_g">B.  
//启动子线程 L QjsOo  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !A%<#Gjt  
for(int i=0;i<nStartPos.length;i++) +a*tO@HG  
{ \G-KplKS  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &~W:xg(jN  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cH>%r^G\  
nStartPos,nEndPos,i); l<N}!lG|  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ."FuwKSJCo  
fileSplitterFetch.start(); KIWe@e  
} %dY<=x#b  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xNbPsoK  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &iV,W4  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", o^ XtU5SVq  
nEndPos = " + nFileLength); []D@Q+1  
// fileSplitterFetch[nPos.length-1].start(); [p<w._b i  
^yOZArc'r  
F;]%V%F.X  
//等待子线程结束 -a-(r'Qc(  
//int count = 0; @*sWu_ -Y%  
//是否结束while循环 =%/)m:f!^  
boolean breakWhile = false; YIjTL!bA"  
GI&h`X5,e  
KVJ_E!i  
while(!bStop) y99mC$"Ee`  
{  #B\" '8#  
write_nPos(); !50[z:  
Utility.sleep(500); IC7M$  
breakWhile = true; [Vma^B$7Vj  
qT^I?g"!  
Ng_!zrx04  
for(int i=0;i<nStartPos.length;i++) ,2W8=ON  
{ rvw)-=qR[  
if(!fileSplitterFetch.bDownOver) hvaSH69*m  
{ 5;HH4?]p  
breakWhile = false; hodgDrmO/  
break; |vw"[7_aS  
} B $mX3B+a  
} K1T4cUo  
if(breakWhile) )vSRHE  
break; 5D'\b}*lJ}  
k`N^Vdr  
5s]. @C8  
//count++; >:b Q  
//if(count>4) @/31IOIV]`  
// siteStop(); ^- d%r  
} sQ\8>[]   
*Em,*!  
^N)R=tl  
System.err.println("文件下载结束!"); tdu$pC6  
} p}~qf  
catch(Exception e){e.printStackTrace ();} 1aTB%F  
} :*KHx|Q  
_FWBUZ;N  
U-3i  
//获得文件长度 [)TRTxFb  
public long getFileSize() .Fp4: e  
{ N}t 2Nu-  
int nFileLength = -1; Ll4g[8  
try{ 5bg s*.s  
URL url = new URL(siteInfoBean.getSSiteURL()); sL$:"=  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )<tI!I][j  
httpConnection.setRequestProperty("User-Agent","NetFox"); zld#qG6  
\vO,E e~#W  
5yz(>EVH  
int responseCode=httpConnection.getResponseCode(); _BP&n  
if(responseCode>=400) ;N?]eM}yf  
{ p|p l  
processErrorCode(responseCode); 53n^3M,qK  
return -2; //-2 represent access is error ;67x0)kn  
} LBZ+GB  
AnX%[W "  
e\:+uVzz  
String sHeader; [wzb<"kW  
s|y "WDyx5  
z.;ez}6%V  
for(int i=1;;i++) 71t* %  
{ lp^<3o*1  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u@cYw:-C  
//Utility.log(in.readLine()); #*UN >X  
sHeader=httpConnection.getHeaderFieldKey(i); Rw0qcM\>|  
if(sHeader!=null) |3KLk?2  
{  ^0 \  
if(sHeader.equals("Content-Length")) ?m\t| /0Q  
{ aq@8"b(.  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #$8% w  
break; ", KCCis  
} @y\X R  
} i=oU;7~zK  
else )`O~f_pIC  
break; )O@]uY  
} VL` z[|e @  
} ia+oX~W!VR  
catch(IOException e){e.printStackTrace ();} Su/6Q$0 t  
catch(Exception e){e.printStackTrace ();} N@Uy=?)ZJ  
LAS'u "c|  
IHv[v*4:  
Utility.log(nFileLength); 9^#c| 0T  
E vg_q>  
Eu@huN*/  
return nFileLength; S(*sw 0O@+  
} %_%Q 8,W  
.Z `av n  
hRD=Y<>A  
//保存下载信息(文件指针位置) :Ra,Eu  
private void write_nPos() Xx0hc 8qd  
{ .7avpOfz  
try{ #PH~1`vl  
output = new DataOutputStream(new FileOutputStream(tmpFile)); lHPd"3HDK  
output.writeInt(nStartPos.length); ORJIo  
for(int i=0;i<nStartPos.length;i++) 1e{IC=  
{ ij(B,Y  
// output.writeLong(nPos); TU,s*D&e  
output.writeLong(fileSplitterFetch.nStartPos); @v)p<r^M">  
output.writeLong(fileSplitterFetch.nEndPos); :2rZcoNb.  
} q(.sq12<<W  
output.close(); 3 09hn  
} I%j|D#qY:T  
catch(IOException e){e.printStackTrace ();} PIoLywpRn  
catch(Exception e){e.printStackTrace ();} 87 $dBb{  
} .yqM7U_  
&;[Io  
gv- xm  
//读取保存的下载信息(文件指针位置) Rnr(g;2  
private void read_nPos() sHt].gZ  
{ y[)>yq y  
try{ ?R$F)g7<  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); qzKdQ&vO  
int nCount = input.readInt(); uXJ;A *  
nStartPos = new long[nCount]; vZaZc}AyL  
nEndPos = new long[nCount]; U4C 9<h&  
for(int i=0;i<nStartPos.length;i++) 2a`o &S  
{ EIf5(/jo  
nStartPos = input.readLong(); kwo3`b  
nEndPos = input.readLong(); KyYMfC  
} $0>60<J  
input.close(); %7IugHH9y  
} K}buH\yco  
catch(IOException e){e.printStackTrace ();} T?tgd J  
catch(Exception e){e.printStackTrace ();} yW1)vD7  
} /_AnP  
4C61GB?Vy  
IoQEtA  
private void processErrorCode(int nErrorCode) z<U-#k7nz  
{ !sQY&*  
System.err.println("Error Code : " + nErrorCode); +eK"-u~K  
} aW)-?(6>  
mD$A4Y-'p  
>~[c|ffyo/  
//停止文件下载 H8Bs<2  
public void siteStop() :t8b39  
{ s%nUaWp~  
bStop = true; %et } A93  
for(int i=0;i<nStartPos.length;i++) .oYl-.E>&  
fileSplitterFetch.splitterStop(); Sq/ qu-%X  
=jOv] /  
`.~N4+SP  
} Rg\z<wPBG  
} fk6%XO  
//负责部分文件的抓取 Pq;U &,  
**FileSplitterFetch.java )wam8k5  
*/ fTS5 yb%  
package NetFox; r@h5w_9  
q<[P6}.  
zZPuha8  
import java.io.*; ;qafT@ }C  
import java.net.*; .h@rLorm>  
"7'J &^|  
~dgDO:)  
public class FileSplitterFetch extends Thread { 0QXVW}`hz  
"}u.v?HYz  
qT{U(  
String sURL; //File URL 8uc1iB  
long nStartPos; //File Snippet Start Position 591>rh)  
long nEndPos; //File Snippet End Position VRWAm>u  
int nThreadID; //Thread's ID 5nv#+ap1 "  
boolean bDownOver = false; //Downing is over :|V$\!o'U  
boolean bStop = false; //Stop identical ieDk;  
FileAccessI fileAccessI = null; //File Access interface ddJQC|xR}  
#%a;"w  
&gVN&  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException dt \TQJc~  
{ 0%9 q8 M;  
this.sURL = sURL; nhB1D-  
this.nStartPos = nStart; p `8 s  
this.nEndPos = nEnd; @Lpq~ 1eZB  
nThreadID = id; 8'r2D+Vwm  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 [-65PC4aN  
} ~P*6ozSYpY  
hm84Aq= f  
|{BIHgMh  
public void run() 8 ##-EN;ag  
{ #a/5SZP Z\  
while(nStartPos < nEndPos && !bStop)  8{wwd:6  
{ kw >v:F<M  
W]"zctE  
Tzt8h\Q^z  
try{ )M,Of Xa  
URL url = new URL(sURL); 63q^ $I  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]e"=$2d$  
httpConnection.setRequestProperty("User-Agent","NetFox"); f/ ?_  
String sProperty = "bytes="+nStartPos+"-"; 9_q#W'/X  
httpConnection.setRequestProperty("RANGE",sProperty); (Mo*^pVr  
Utility.log(sProperty); HmiR.e%<b  
^1S!F-H4\  
0t^M3+nc  
InputStream input = httpConnection.getInputStream(); ?J%1#1L"/  
//logResponseHead(httpConnection); 7]U"Z*  
h;C5hU 4P  
35Ij ..z0  
byte[] b = new byte[1024]; 54gBJEhg  
int nRead; 1Ce@*XBU  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) yQ_B)b  
{ H7z,j}l  
nStartPos += fileAccessI.write(b,0,nRead); )JDs\fUE  
//if(nThreadID == 1) 09X01X[  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos);  ,V,`Jf  
} ^!<U_;+  
I?h)OvWd  
!^^?dRd*v  
Utility.log("Thread " + nThreadID + " is over!"); L6t+zIUc-~  
bDownOver = true; Vi>,kF.f V  
//nPos = fileAccessI.write (b,0,nRead); TTeH `  
} n&{Dq}q  
catch(Exception e){e.printStackTrace ();} {'XggI%  
} R?GDJ3  
} gQo]  
;\a YlV-  
%7"q"A r[  
//打印回应的头信息 _BM" ]t*  
public void logResponseHead(HttpURLConnection con) Ee)T1~;W  
{ >QjAoDVX?  
for(int i=1;;i++) X}=n:Ql'YY  
{ ^`*9QjY  
String header=con.getHeaderFieldKey(i); 3)F |*F3R  
if(header!=null) =!kk|_0%E  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); M`. tf_x  
Utility.log(header+" : "+con.getHeaderField(header)); !S^AgZ~  
else G<At_YS  
break; 0C =3dnp6  
} v/Py"hQ  
} 1{r3#MVL  
3/aMJR:o  
x*![fK  
public void splitterStop()  ~3Lg"I  
{ i'a?kSy  
bStop = true; .\[`B.Q  
} xAqb\|$^  
w zYzug  
K0H'4' I  
} Of- Rx/  
p6 ]7&{>  
E.r>7`E  
/* "8c@sHk(w  
**FileAccess.java $&y%=-]|  
*//文件访问(定位,写) T?:Rdo!:u  
package NetFox; u5O+1sZ"6  
import java.io.*; GS0;bI4ay  
o}$XH,-9&  
9)y/:sO<P  
public class FileAccessI implements Serializable{ _76PIR{an  
yL%K4$z  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 y-T| #  
RandomAccessFile oSavedFile; ^M3~^lV  
long nPos; )` SE S."  
!Nu<xq@!  
zAK+8{,  
public FileAccessI() throws IOException {!.(7wV\  
{ VO,!x~S!  
this("",0); RS"H8P 4W  
} e>7]w,*|  
u}>#Eb  
)'Oh `$M  
public FileAccessI(String sName,long nPos) throws IOException $56Z#'(D  
{  V_C-P[2~  
oSavedFile = new RandomAccessFile(sName,"rw"); AjmVc])  
this.nPos = nPos; ^@ I   
oSavedFile.seek(nPos); Ao&\EcIOT  
} G'rxXJq  
3 ;)>Fs;  
IM:=@a{  
public synchronized int write(byte[] b,int nStart,int nLen) |M>eEE*F<  
{ 6BY-^"W5`  
int n = -1; !(mjyr  
try{ K\>tA)IPSV  
oSavedFile.write(b,nStart,nLen); kd=GCO  
n = nLen; __`*dL>*  
} b_,|>U  
catch(IOException e) *YW/_  
{ 8;z6=.4xtg  
e.printStackTrace (); IYqBQnX}oM  
} @En^wN  
g3Ec"_>P  
Mx6@$tQ%  
return n; M^MdRu  
} l*ayd>`~x  
\qR7mI/*  
`Y BC  
} INcg S MM  
X- pqw~$  
7q?9Tj3  
/* F|F]970  
**SiteInfoBean.java ICuF %  
*/ P1zKsY,l$<  
package NetFox; rW0kA1=E  
ZZWD8 AX  
cnSJ{T  
public class SiteInfoBean { sqla}~CiX  
'HT7_$?*  
P.6nA^hXB  
private String sSiteURL; //Site's URL 5 elw~u  
private String sFilePath; //Saved File's Path E_Im^a  
private String sFileName; //Saved File's Name 8 ![|F:  
private int nSplitter; //Count of Splited Downloading File ,O.3&Nz,c  
CJ(NgYC h  
 '/`= R  
public SiteInfoBean() eKgisY4#  
{//nSplitter的缺省值为5 y@ ML/9X8q  
//default value of nSplitter is 5 7 ]^M>#  
this("","","",5); (>F%UY  
} SLO%7%>p  
6Ca(U'  
C2@,BCR  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ol1e/Wv  
{ nFE4qm  
sSiteURL= sURL; =3|O %\  
sFilePath = sPath; c05TsMF&O  
sFileName = sName; -%2[2p  
this.nSplitter = nSpiltter; ;ToKJ6hN|*  
HuB<k3#sPy  
S7=Bd[4  
} q+P|l5_ t  
aT_&x@x  
>fe- d#!{  
public String getSSiteURL() umD!2 w  
{ AP[|Ta  
return sSiteURL; %R@X>2l/_  
} 7+]=-  
`^bgUmJ~  
D-8O+.@  
public void setSSiteURL(String value) thV>j9'  
{ 6;C3RU]  
sSiteURL = value; :q=%1~Idla  
} #~SP)Ukp  
1=#q5dZ]  
/<E5"Mm%  
public String getSFilePath() Ge,;8N88  
{ Xua+cVc\y  
return sFilePath; !vX D  
} yMyE s8  
7G.#O}).b  
*&?c(JU;<  
public void setSFilePath(String value) HU%o6cw  
{ /b]oa !  
sFilePath = value; vLR~'" `F  
} *\=.<|HZ  
~GTz:nC*  
u@~JiiC%  
public String getSFileName() 4$qWiG~  
{ ELBa}h;  
return sFileName; ,z3{u162  
} "J+3w  
~2<7ZtV=  
'6Ay&A3N]  
public void setSFileName(String value) CF+_/s#j^  
{ 350_CN,  
sFileName = value; u`y><w4i  
} T6H}/#*tK  
MxSM@3v(  
)ap_Z6  
public int getNSplitter() 3= xhoRX  
{ /V8}eZ97  
return nSplitter; \zieyE  
} (Q%'N3gk  
~\=1'D^6CK  
7:9.&W/KE  
public void setNSplitter(int nCount) /J04^ 6  
{ ,S'p %g  
nSplitter = nCount; XEn*?.e  
} _{R=B8Zz\  
} Jj,U RD&0R  
G"X8}:}  
R<sJ^nx  
/* qtiz a~u  
**Utility.java 4!+pc-}-  
*/ _/Gczy4)#  
package NetFox; V6t,BJjS  
h.-@ F  
~.A)bp  
public class Utility { 5O~HWBX.  
Mr?Xp(.}G  
SV:4GVf  
public Utility() HHq_P/'  
{ G2t;DN(  
{.Z}5K  
5WC+guK7  
} [|P!{?A43|  
SG-'R1 J  
//线程睡眠 }:u~K;O87  
public static void sleep(int nSecond) FL(6?8zK  
{ Y^ kXSU  
try{ vFE;D@bz:  
Thread.sleep(nSecond); ta`N8vnf  
} $-#Yl&?z9  
catch(Exception e) PUo/J~v  
{ Q-MQ9'  
e.printStackTrace (); X>NhZ5\  
}  1WY/6[  
} S/Fkw4%  
2>86oP&  
//日志 mjWU0Gh%*  
public static void log(String sMsg) yHHt(GM|o  
{ #{k|I$  
System.err.println(sMsg); f>piHh?  
} h3*Zfl<]  
MF~H"D n  
(q{Ck#+  
public static void log(int sMsg) ZKQG:M~|  
{ @;<ht c  
System.err.println(sMsg); jV? }9L^;  
} _Qh z3'I1  
} ?T>'j mmV=  
z;A>9vQ_J  
R,9[hNHWGs  
/* Row)hx8  
**TestMethod.java 3 n'V\H vz  
*/ L]d-hs  
package NetFox; ]Ar\c["  
D8>enum  
 EI_  
public class TestMethod { ?[)}l9  
uiJS8(Cb  
g.'yZvaP  
public TestMethod() fv`O4  
{ ///xx/weblogic60b2_win.exe x9x E&  
try{ 87:!C5e}  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 5B&;uY  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 4hAl-8~Q6  
SiteFileFetch fileFetch = new SiteFileFetch(bean); D\[h:8k  
fileFetch.start(); ~er\~kp  
} :>TEDy~O%  
catch(Exception e){e.printStackTrace ();} &v"3*.org@  
VH=S?_RY>  
oS7(s  
} \3'9Uz,OC  
aX~%5 mF  
DyQM>xw)t  
public static void main(String[] args) Wx~k&[&E  
{ <{2e#Y  
new TestMethod(); !-N6l6N  
} M/):e$S  
} ?0YCpn  
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