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http断点续传简单实现(java)

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/* jWi~Q o+  
**SiteFileFetch.java vq+CW?*"  
*/ oSkQ/5hg.  
package NetFox; T6=|)UTe1  
import java.io.*; tgi%#8ZDpz  
import java.net.*; y"'p#j  
Pc< "qy  
q9j~|GE|  
public class SiteFileFetch extends Thread { eB1NM<V  
f5b|,JJ  
3!fR'L/i  
SiteInfoBean siteInfoBean = null; //文件信息Bean &0%Z b~ts  
long[] nStartPos; //开始位置 F --b,,  
long[] nEndPos; //结束位置 j%-Ems*H  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~ho,bwJM[T  
long nFileLength; //文件长度 C/qKa[mg  
boolean bFirst = true; //是否第一次取文件 @fp@1n  
boolean bStop = false; //停止标志 k3@d = k  
File tmpFile; //文件下载的临时信息 i$@xb_  
DataOutputStream output; //输出到文件的输出流 D6&P9e_5  
]BjY UTNm  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) HQ" trV  
public SiteFileFetch(SiteInfoBean bean) throws IOException }zsIp,  
{ 9lR6:}L7  
siteInfoBean = bean; V;"2=)X  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); KW[y+c u.#  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); q0Q[]|L  
if(tmpFile.exists ()) jQ%1lQ#R)  
{ Mog [,{w  
bFirst = false; C,W_0= !e  
read_nPos(); A:GqR;;"x>  
} HJ]e%og  
else 1Td`S1'#yg  
{ .S#i/A'x  
nStartPos = new long[bean.getNSplitter()]; |9]-_a  
nEndPos = new long[bean.getNSplitter()]; qK#"uU8B  
} zF[Xem  
) xa )$u  
$hcv}<$/  
@<pd@Mpf]  
} W,Q>3y*  
 aY(s &  
DT>`.y%2W  
public void run() F9K`N8wlu  
{ iv6G9e{cx  
//获得文件长度 ,&=7ir14>R  
//分割文件 j y5[K.  
//实例FileSplitterFetch % H"  
//启动FileSplitterFetch线程 5CN=a2&  
//等待子线程返回 JmK )Y# A  
try{ %M'`K  
if(bFirst) wzwv>@}  
{ a6./;OC  
nFileLength = getFileSize(); Ib{l$#  
if(nFileLength == -1) ?&eS}skL  
{ 6V1oZ-:}  
System.err.println("File Length is not known!"); | |pOiR5  
} W$SV+q(rT  
else if(nFileLength == -2) #iv4L  
{ SH=S>  
System.err.println("File is not access!"); I5l%X{u"N  
} JkT!X  
else 85Yi2+8f4  
{ '[F`!X  
for(int i=0;i<nStartPos.length;i++) hp2E! Cma  
{ \-6y#R-B  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); !h7:rv/  
} *qSvSY*  
for(int i=0;i<nEndPos.length-1;i++) zx=eqN@!@  
{ F)Q[ cai  
nEndPos = nStartPos[i+1]; !]g[u3O  
} U+B"$yBR  
nEndPos[nEndPos.length-1] = nFileLength; 1) 2-UT  
} V )oXJL  
} f['lY1#V1  
6c-'CW  
=lk'[P/p`  
//启动子线程 $A{$$8P  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f:~G)  
for(int i=0;i<nStartPos.length;i++) <|Lz#iV37  
{ [u K,.G  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UV}:3c6ZX  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), :M{ )&{D  
nStartPos,nEndPos,i); HP[B%  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {-me;ayk  
fileSplitterFetch.start(); @^YXE,  
} cRr3!<EZ  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K3 BWj33  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x  zF  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", YB4 ZI  
nEndPos = " + nFileLength); OQ_< Vxz  
// fileSplitterFetch[nPos.length-1].start(); W? 4:sLC#3  
Y#V(CIDe  
x+6z9{O  
//等待子线程结束 'h6G"=+  
//int count = 0; O^-QqCZE  
//是否结束while循环 gTTKjlI [  
boolean breakWhile = false; R,PN?aj  
sgK =eBE  
t/O^7)%  
while(!bStop) ?;P6#ByR  
{ pn(i18 x  
write_nPos(); ]3*w3Y!XK  
Utility.sleep(500); vW*Mf}=  
breakWhile = true; RPeH[M^  
v*GS>S  
dZ(Z]`L,B  
for(int i=0;i<nStartPos.length;i++) )hO%W|  
{ k}<H  
if(!fileSplitterFetch.bDownOver) l }^ziY!  
{ =#9#unvE!  
breakWhile = false; qG 20  
break; } #e=*8F7  
} j1{`}\e  
} }6%\/d1~ 6  
if(breakWhile) t-C|x)J+  
break; ]Bf1p  
>E4,zs@7t  
|iBf6smF  
//count++; CT|0KB&  
//if(count>4) UQh.o   
// siteStop(); 8h|}Q_  
} sRcd{)|Cq  
y,&[OrCm^\  
&4WA/'>R  
System.err.println("文件下载结束!"); }15&<s  
} ~$4(|Fq/  
catch(Exception e){e.printStackTrace ();} UYZC% $5x  
} UIf#Gy|l  
(NR( )2  
`&fW<5-  
//获得文件长度 =d5;F`m  
public long getFileSize() >T [Y>]  
{ `fEzE\\!*  
int nFileLength = -1; [|*7"Q(  
try{ u?SwGXi~8  
URL url = new URL(siteInfoBean.getSSiteURL()); cOpe6H6,bz  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); tk'&-v'h  
httpConnection.setRequestProperty("User-Agent","NetFox"); wV f 7<@/y  
mk~CE  
MhE".ZRd  
int responseCode=httpConnection.getResponseCode(); 7oIHp_Zq  
if(responseCode>=400) "u~` ZV(  
{ H*<E5^#dw  
processErrorCode(responseCode); ke W7pN?  
return -2; //-2 represent access is error r>bgCQ#-n  
} O!dS;p-F  
 }+/Vk  
xh#_K@8  
String sHeader; Jg'#IM  
6 .?0 {2s  
9 $X" D  
for(int i=1;;i++) 0$Mxu7 /  
{ Sb2_&5  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T^7}Qs9  
//Utility.log(in.readLine()); 'Bt!X^  
sHeader=httpConnection.getHeaderFieldKey(i); Gy["_;+xU  
if(sHeader!=null) .c<U5/  
{ R1Rk00Ow:  
if(sHeader.equals("Content-Length")) _/P;`@  
{ F)eP55C6  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =m (u=|N3  
break; 0k\,z(e  
} CHqi5Z/+  
} ak:f4dEd  
else b9?Vpu`?  
break; 5GJkvZtFY  
} ='kCY}dkO  
} o(54 A['  
catch(IOException e){e.printStackTrace ();} n>Oze7hVY  
catch(Exception e){e.printStackTrace ();}  1 <T|  
%|JL=E}%|  
V:5aq.o!  
Utility.log(nFileLength); m$_l{|4z  
*tpS6{4=#7  
A 9l d9R  
return nFileLength; 9 {SzE /[  
} c1_Zi  
n'pJl  
ON!Fk:-  
//保存下载信息(文件指针位置) @ kv~2m  
private void write_nPos() 0;`FS /[(f  
{ %UooZO  
try{ # 7d vT=  
output = new DataOutputStream(new FileOutputStream(tmpFile)); wt@TR~a  
output.writeInt(nStartPos.length); IR2Qc6+{  
for(int i=0;i<nStartPos.length;i++) @0H0!9'  
{ @m`H~]AU  
// output.writeLong(nPos); V{>;Z vj1R  
output.writeLong(fileSplitterFetch.nStartPos); wS7Vo{#@\  
output.writeLong(fileSplitterFetch.nEndPos); -3d`e2^&}  
} :si&A;k  
output.close(); ^oq|^O  
} L?8OWLjRy  
catch(IOException e){e.printStackTrace ();} DTi^* Wj  
catch(Exception e){e.printStackTrace ();} vYLspZ;S  
} w0sy@OF  
 C. uv0  
_M;{}!Gc&A  
//读取保存的下载信息(文件指针位置) ca0vN^Ji  
private void read_nPos() ^a3 (QKS  
{ W95q1f# 7  
try{ 7}c[GC)F  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %O[1yZh \  
int nCount = input.readInt(); FoYs<aER  
nStartPos = new long[nCount]; %t9Kc9u3p  
nEndPos = new long[nCount]; +",`Mb  
for(int i=0;i<nStartPos.length;i++) 16z Wm JH  
{ 9"B;o  
nStartPos = input.readLong(); U~7{q >  
nEndPos = input.readLong(); lQ [JA[  
} K'"s9b8  
input.close(); Mjl,/-0 w  
} 6+s&%io4  
catch(IOException e){e.printStackTrace ();} $j(4FyH\  
catch(Exception e){e.printStackTrace ();} X9" T(`  
} 'f %oL/,  
^pfM/LQ@  
8"ZcKxDk  
private void processErrorCode(int nErrorCode) oz3!%'  
{ f::^zAV  
System.err.println("Error Code : " + nErrorCode); T2|<YJ=  
} $'#}f?  
:=q9ay   
@\-*aS_8>  
//停止文件下载 MScUrW!TA  
public void siteStop() v33[Rk'  
{ Fo ,8"m  
bStop = true; `-W4/7  
for(int i=0;i<nStartPos.length;i++) NFur+zwv  
fileSplitterFetch.splitterStop(); Vj)"?|V  
BTA2['  
<X1[j9Qtv0  
} %.uN|o&n  
} I;$tBgOWq  
//负责部分文件的抓取 !+ UXu]kA  
**FileSplitterFetch.java eIP k$j{e  
*/ x< d ew  
package NetFox; ~7\`qH  
)kKeA  
3%x-^.  
import java.io.*; 9]{Ss$W3x  
import java.net.*; t[b(erO'  
B(- F|q\  
fl_a@QdB#  
public class FileSplitterFetch extends Thread { 'P&r^V\~(/  
J04R,B  
\naG  
String sURL; //File URL :2{ [f+  
long nStartPos; //File Snippet Start Position >Ij# +=  
long nEndPos; //File Snippet End Position l,b_' m@  
int nThreadID; //Thread's ID qX[C%  
boolean bDownOver = false; //Downing is over +$^ [ r  
boolean bStop = false; //Stop identical [R~@#I P!  
FileAccessI fileAccessI = null; //File Access interface D2:ShyYAS  
k5)IBO  
G6"4JTWO  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException y dzvjp=  
{ cf_X=;yaqy  
this.sURL = sURL; qNkX:|j  
this.nStartPos = nStart; yW_goS0  
this.nEndPos = nEnd; %Si3LQf  
nThreadID = id; N,cj[6;T%  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Z>'hNj)ju  
} MB.LHIo  
MY&?*pV)  
V5I xZn%  
public void run() \]L h a  
{ ,#.^2O9-^  
while(nStartPos < nEndPos && !bStop) 3ZYrNul"  
{ rN {5^+w  
`zcpaE.@  
&#]||T-  
try{ 34vH+,!u  
URL url = new URL(sURL); -r{]9v2j  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yv5c0G.D  
httpConnection.setRequestProperty("User-Agent","NetFox"); {JcMJZ3  
String sProperty = "bytes="+nStartPos+"-"; @Z~0!VY  
httpConnection.setRequestProperty("RANGE",sProperty); Ti5"a<R4m6  
Utility.log(sProperty); 3SOrM  
x C>>K6Nb  
)q%DRLD'G  
InputStream input = httpConnection.getInputStream(); @hOY&  
//logResponseHead(httpConnection); hN1{?PQ  
j0e1CSE  
K5d>{c  
byte[] b = new byte[1024]; xkz`is77Y@  
int nRead; q +c~Bd  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) o6:p2W  
{ `+WQ^dP@  
nStartPos += fileAccessI.write(b,0,nRead); 4wwRNu*  
//if(nThreadID == 1) PF;`mdi-,  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !=+hU/e  
} ?eR^\-e  
`&A-m8X  
S3 /Z]?o  
Utility.log("Thread " + nThreadID + " is over!"); EPeV1$  
bDownOver = true; }Ot2; T  
//nPos = fileAccessI.write (b,0,nRead); 54&&=NVs|  
} gO! :WD  
catch(Exception e){e.printStackTrace ();} *wz62p  
} #!M;4~Sfx  
} HG})V PBa  
mz .uK2l{  
ob=IaZ@?  
//打印回应的头信息 9KZLlEk5O  
public void logResponseHead(HttpURLConnection con) g*:f#u5  
{ e&="5.ik  
for(int i=1;;i++) Pexg"328  
{ )G9,5[  
String header=con.getHeaderFieldKey(i); Ob7F39):N  
if(header!=null) 7ZpU -':  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); e p\a  
Utility.log(header+" : "+con.getHeaderField(header)); "V7&@3  
else as@I0e((  
break; ).>O6A4:C  
} ,N5-(W  
} N7qSbiRf<  
lV<j?I~?Q  
R&s\h"=*  
public void splitterStop() I!,FxOM|$  
{ 9xUAfU  
bStop = true; Sc$]ar]S  
} nSV OS6  
PF/eQZ*4  
25`6V>\  
} (K->5rSU  
^<'=]?xr  
=wX(a  
/* W-@}q}A  
**FileAccess.java l8ZzKb-  
*//文件访问(定位,写) &]HY:  
package NetFox; 62%=%XD  
import java.io.*; #s^~'2^%4  
v`pIovn  
@Vac!A??:  
public class FileAccessI implements Serializable{ skn];%[v\  
2=xjgK  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ycve[31BDd  
RandomAccessFile oSavedFile; *b]$lj  
long nPos; go$zi5{h#  
SdBo sB3v>  
Q+'QJ7fw'|  
public FileAccessI() throws IOException ,v+~vXO&\  
{ _kT$/k  
this("",0); E h>qUa  
} k9?fE  
2_lb +@[W  
ey>V^Fj  
public FileAccessI(String sName,long nPos) throws IOException } ^67HtNQ  
{ 8DP] C9  
oSavedFile = new RandomAccessFile(sName,"rw"); =7uxzg/%Tj  
this.nPos = nPos; D^9r#&  
oSavedFile.seek(nPos); Y5Jrkr)k  
} -*Z;EA-  
ht%:e?@i  
%JC-%TRWK  
public synchronized int write(byte[] b,int nStart,int nLen) 7 xm>+(  
{ c:MP^PWc  
int n = -1; IH1 fvW e  
try{ H$i4OQ2  
oSavedFile.write(b,nStart,nLen); U6@ j=|q  
n = nLen; #^fDKM  
} `-L{J0xq  
catch(IOException e) VCZ.{MD  
{ 0W I3m2i  
e.printStackTrace (); RZV6\ j  
} {\+!@?  
R3SAt-IE  
kG>d^K  
return n; ^ LT KX`p  
} \-B8`ah  
J2W:Q  
R4Vi*H  
} {m/h3hjFa  
]N+(SU  
WM_wkvY l  
/* ,KHebv!  
**SiteInfoBean.java \]eB(&nq  
*/ OZ6g u$ n*  
package NetFox; -mlBr63Bj  
.Bu?=+O~  
({}JvSn1  
public class SiteInfoBean { eS/4gM7%  
fH/J8<  
- W5ml @  
private String sSiteURL; //Site's URL  k_;+z  
private String sFilePath; //Saved File's Path xu _:  
private String sFileName; //Saved File's Name  X)^kJ`  
private int nSplitter; //Count of Splited Downloading File #sK:q&/G`  
l |c#  
`}YCUm[SI  
public SiteInfoBean() *uq;O*s  
{//nSplitter的缺省值为5 O%.c%)4Xo  
//default value of nSplitter is 5 pLvvv#Y  
this("","","",5); `|\z#Et  
} ;LM,<QJ  
7LM?<lp]  
HH+$rrTT  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) h`0'27\C  
{ ySLa4DQf  
sSiteURL= sURL; :eIu<_,}  
sFilePath = sPath; %\5d?;   
sFileName = sName; {uQp$`  
this.nSplitter = nSpiltter; i,DnXgmz@  
k<098F  
}&Gt&Hm>K  
} 9b8ZOk'9_  
#R<ErX)F  
478gl o  
public String getSSiteURL() ]YP J.[n  
{ O|opNr  
return sSiteURL; M7|k"iz v  
} i1"4z tZ  
Vu3;U  
M~Tx 4_t  
public void setSSiteURL(String value) t<Iy `r7 1  
{ F|t3%dpj  
sSiteURL = value; }6;v`1Hr  
} Z9MT, "  
f,ajo   
IXaF(2>  
public String getSFilePath() MY]Z@  
{ a&3pPfC  
return sFilePath; dVh*  a  
} h7iI=[_V  
%. =B=*  
'$@bTW  
public void setSFilePath(String value) #Ont1>T,G  
{ bn b:4?d]  
sFilePath = value; DdY89R 6  
} /~?'zr  
~|_s2T  
0:Ow$  
public String getSFileName() `@$qy&AJ  
{ +=v6 *%y"V  
return sFileName; )*=ds ,  
} .</`#   
3]=j!_yJf  
|;XkU`G  
public void setSFileName(String value) 9"5J-a'  
{ 3dlL?+Y#  
sFileName = value; z@Klj qN  
} RqV* O}Am  
osS?SuQTE  
MlDWK_y_&  
public int getNSplitter() W+v7OSd92  
{ PyOj{WX>W  
return nSplitter; jA&ZO>4  
} ^W&qTSjh  
U}w,$ Y  
jF5Y-CX  
public void setNSplitter(int nCount) 5%+M:B  
{ v{/z`J!JR  
nSplitter = nCount; f@3?kM(  
} o5NV4=  
} yfq Vx$YL  
%r1NRg8  
Y[=X b  
/* -@6R`m= >  
**Utility.java m&o6j>C  
*/ xc4g`Xi  
package NetFox; _$g2;X >  
(!^i6z0Sp  
4<j)1i=A  
public class Utility { !fwMkws  
! ^~ ^D<  
n};:*N! v  
public Utility() 7Nu.2qE  
{ /$w,8pV =  
,".1![b  
|ia#Elavo  
} nY]5pOF:  
wZ&l6J4L  
//线程睡眠 WOw( -  
public static void sleep(int nSecond) )Z.v fc  
{ 3sh}(  
try{ 2P`Z >_  
Thread.sleep(nSecond); :5YL!D/&  
} DZ-2Z@{PX  
catch(Exception e) [;?CO<  
{ aYJTSgW  
e.printStackTrace (); ku8C#%.m3  
}  I&m C  
} ~AqFLv/%  
[&Yrnkgr  
//日志 IE^xk@  
public static void log(String sMsg) 'AU:[eyUV  
{ %5?Zjp+9  
System.err.println(sMsg); "s$$M\)T  
} thT2U8%T  
8h,>f#)0c  
r |H 1Yy  
public static void log(int sMsg)  ;rH<  
{ xaPaK-  
System.err.println(sMsg); LqZsH0C  
} `>i8$q%  
} @N tiT,3k  
%< ^IAMkp  
QPc4bg\J~t  
/* ZOAHM1ci  
**TestMethod.java &nKb<o  
*/ <"GgqyRzv  
package NetFox; WQJnWe   
?M<q95pL  
3PLYC}Jq  
public class TestMethod { PVCFh$pnw  
0*=[1tdWY  
yi29+T7j4S  
public TestMethod() UrMEL; @g  
{ ///xx/weblogic60b2_win.exe n+'gVEBA  
try{ Em<B 9S  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); b.N$eJlQ&  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f/?uo sS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); #YiphR&  
fileFetch.start(); 5YZh e4R  
} MWl2;qi  
catch(Exception e){e.printStackTrace ();} )z" .lw  
%X5p\VS\7  
;4MC/Q/  
} ^MXW,xqb  
y#B4m`9  
~x-"?K  
public static void main(String[] args) D&dh>Pe1;  
{ <n;9IU  
new TestMethod(); !l(O$T9 T  
} "mtEjK5  
} rk E;OU  
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