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http断点续传简单实现(java)

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/* /Z " 4[  
**SiteFileFetch.java 56Y5kxmi  
*/ :J`!'{r  
package NetFox; OPY/XKyY,  
import java.io.*; 'HWgvmw(  
import java.net.*; bus=LAJt=  
FFeRE{,  
|J Q:.h  
public class SiteFileFetch extends Thread { ;v +uv f  
`O=;E`ep  
z#J/*712  
SiteInfoBean siteInfoBean = null; //文件信息Bean WQLL[{mhS  
long[] nStartPos; //开始位置 TJ[jZuT:  
long[] nEndPos; //结束位置 0*;9CH=BE  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 DVoV:pk  
long nFileLength; //文件长度 q&$0i   
boolean bFirst = true; //是否第一次取文件 3d'ikkXK  
boolean bStop = false; //停止标志 y [9}[NMZ  
File tmpFile; //文件下载的临时信息 A%*DQ1N  
DataOutputStream output; //输出到文件的输出流 To8v#.i  
}Q=se[((  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) Zc3:9   
public SiteFileFetch(SiteInfoBean bean) throws IOException c^Gwri4  
{ , q@(L  
siteInfoBean = bean; &/hr-5k  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); ar qLp|  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); y[WYH5 &DJ  
if(tmpFile.exists ()) D ,ZNh1xt  
{ #8f"}>U9.,  
bFirst = false; .-u k   
read_nPos(); txfwLqx  
} Pv-V7`{  
else lzy$.H"W  
{ mERZ_[a2  
nStartPos = new long[bean.getNSplitter()]; _ K+V?-=  
nEndPos = new long[bean.getNSplitter()]; 0HJqsSZ$mW  
} 2V2x,!  
UE,~_hp  
%cr]ZR  
PDq}Tq  
} LYy:IBI7_  
T3t~=b>&L  
)Kk(P/s  
public void run() Fma`Cm.  
{ mf;^b.mKh  
//获得文件长度 t6%xit+  
//分割文件 FP'u)eU&3  
//实例FileSplitterFetch \eMYw7y5 M  
//启动FileSplitterFetch线程 J]Gc  
//等待子线程返回 &iND&>?  
try{ 4}8+)Pd  
if(bFirst) a,57`Ks+n<  
{ !Ir1qt8 T  
nFileLength = getFileSize(); 7z&adkG:  
if(nFileLength == -1) -90ZI1O`  
{ F%_,]^ n[  
System.err.println("File Length is not known!"); 3n84YX{  
} zsMw5C  
else if(nFileLength == -2) gLxT6v5wk.  
{ *L4]\wf  
System.err.println("File is not access!"); _czbUl  
} '^F|k`$r  
else \;B$hT7z*  
{ Zn<(,e  
for(int i=0;i<nStartPos.length;i++) Gx h~  
{ K* _{Rs0P  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); _> |R-vQ8  
} V:F+HMBk  
for(int i=0;i<nEndPos.length-1;i++) >0<KkBH  
{ H7tQ#  
nEndPos = nStartPos[i+1]; 93^(O8.  
} o3i,B),K  
nEndPos[nEndPos.length-1] = nFileLength; Xc9p;B>^Ts  
} <(bCz>o|  
} R%)2(\  
iA%' ;V  
@!&Jgg53G  
//启动子线程 #lyM+.T  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K[#v(<)  
for(int i=0;i<nStartPos.length;i++) Qw6KX#n  
{ p-i.ITRS  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uzVG q!'H  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I_zk'  
nStartPos,nEndPos,i); {+/ .5  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -lP )  
fileSplitterFetch.start(); w$b+R8.n)  
} {7K'<ti  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oc3dd"8}@  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); @tE&<[e  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Rg8m4xw  
nEndPos = " + nFileLength); s}[A4`EWH  
// fileSplitterFetch[nPos.length-1].start(); 38w.sceaT  
C)J_lI{^  
s0 \f9D  
//等待子线程结束 q lz9&w  
//int count = 0; ;e~{TkD  
//是否结束while循环 Msv*}^>  
boolean breakWhile = false; o8};e  
1Es*=zg  
Y0Hq+7x  
while(!bStop) +#-kIaU  
{ ^&`sWO@=  
write_nPos(); Mz/]DJ8  
Utility.sleep(500); +gbX}jF0%  
breakWhile = true; )p/=u@8_f  
3WO#^}t  
t?]\M&i&  
for(int i=0;i<nStartPos.length;i++) kW<Yda<a  
{ pBg|n=^  
if(!fileSplitterFetch.bDownOver) b"R, p=M  
{ 5#TrCPi6A  
breakWhile = false; KdOh'OrT9.  
break; RV0>-@/x  
} z)58\rtz  
} ,Lt~u_lve  
if(breakWhile) .g/ARwM}  
break; C@TN5?Z  
{[M0y*^64$  
o~OwE7H)A  
//count++; '!j #X_;  
//if(count>4) C=oM,[ESQ0  
// siteStop(); ?q d,>  
} i\kTm?BQZ  
QMXD9H0{  
O8K@&V p  
System.err.println("文件下载结束!"); wMH[QYb<*  
} Ss@u,`pr  
catch(Exception e){e.printStackTrace ();} c N02roQl  
} ] ?DDCew  
Q(~3pt  
3W7;f!  
//获得文件长度 krQ l^~@  
public long getFileSize() <mv7HKVg  
{ Je#!Wd  
int nFileLength = -1; ~_DF06G  
try{ /<3;0~#){  
URL url = new URL(siteInfoBean.getSSiteURL()); |eH wp  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g9yaNelDh)  
httpConnection.setRequestProperty("User-Agent","NetFox"); Veb+^&  
Lv `#zgo_f  
?1GY%-  
int responseCode=httpConnection.getResponseCode(); ^l Hb&\X  
if(responseCode>=400) Qqd6.F  
{ -Z:]<;qU  
processErrorCode(responseCode);  /6+1{p  
return -2; //-2 represent access is error w)45SZ.  
} B#HV20\?v  
+V)qep"  
}1U#Ve,=_  
String sHeader; P'a0CE%  
qn2o[x  
E:uReT  
for(int i=1;;i++) t{/hkXq]  
{ ,sO:$  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ZWf-X  
//Utility.log(in.readLine()); q*~gWn>T  
sHeader=httpConnection.getHeaderFieldKey(i); GY oZ$p"C  
if(sHeader!=null) rPRrx-A  
{ !UBy%DN~k  
if(sHeader.equals("Content-Length")) jP1$qhp  
{ O0@w(L-  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6eOrs-ty  
break; mND XzT&  
} NJn&>/vM  
} aQ(`6DQv  
else Z} c'Bm(  
break; i LF^%!:X%  
}  uY.=4l  
} l% rx#;=u  
catch(IOException e){e.printStackTrace ();} cqeR<len  
catch(Exception e){e.printStackTrace ();} /SnynZ.q  
:|Z$3q  
R;H?gE^m-  
Utility.log(nFileLength); 1a<]$tZk  
aRbx   
lkV6qIj   
return nFileLength; "e~k-\^Y  
} S3SV.C:z>  
;knd7SC   
|J:$MX~  
//保存下载信息(文件指针位置) xKY$L*  
private void write_nPos() cvKV95bn  
{ 1s Br.+p  
try{ -u6}T!  
output = new DataOutputStream(new FileOutputStream(tmpFile)); o:_^gJ+|  
output.writeInt(nStartPos.length); sT)6nV  
for(int i=0;i<nStartPos.length;i++) vT?Q^PTO  
{ . 3Gn ZR,L  
// output.writeLong(nPos); }c} ( 5  
output.writeLong(fileSplitterFetch.nStartPos); Yx6hA#7I  
output.writeLong(fileSplitterFetch.nEndPos); RXBb:f  
} W@l+ciZ_  
output.close(); 3@&bxYXm  
} o>2e !7  
catch(IOException e){e.printStackTrace ();} |</"N-#S  
catch(Exception e){e.printStackTrace ();} 6G'<[gL j  
} ([Ebsj  
?8Et[tFg  
wuKl-:S;Vs  
//读取保存的下载信息(文件指针位置) mKV'jm0  
private void read_nPos() 1xz\=HOT  
{ `8,w[o oC2  
try{ PfyRZ[3)c  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); fCB:733H  
int nCount = input.readInt(); w TlGJ$D0  
nStartPos = new long[nCount]; sYI~dU2H  
nEndPos = new long[nCount]; +)gGs# 2X  
for(int i=0;i<nStartPos.length;i++) Wdo#?@m  
{ ,E&Bn8L~O  
nStartPos = input.readLong(); u,f A!  
nEndPos = input.readLong(); v51EXf  
} U| 8[#@r  
input.close(); Xt ft*Z  
} 5^>n5u/  
catch(IOException e){e.printStackTrace ();} _().t5<  
catch(Exception e){e.printStackTrace ();} =HMmrmz:  
} gC`)]*'tE  
1  o|T  
X:_<Y_JT  
private void processErrorCode(int nErrorCode) N<(HPE};  
{ s|Zx(.EP  
System.err.println("Error Code : " + nErrorCode); 8zZSp  
} ^;zWWg/d  
[G a~%m  
&eIGF1ws  
//停止文件下载 m=QCG)s  
public void siteStop() ,>u=gA&}  
{ VpSEVd:n  
bStop = true; &s:=qQa1  
for(int i=0;i<nStartPos.length;i++) @;m$ua*|:  
fileSplitterFetch.splitterStop(); ;`kWpM;  
2/@D7>F&g  
R uLvG+  
} ]M3# 3Ha"  
} .B>B`q;B  
//负责部分文件的抓取 u?kD)5Nk  
**FileSplitterFetch.java W (`c  
*/ 7UKYmJk.  
package NetFox; *zy'#`>  
8%[HYgd5)  
B;!f<"a8  
import java.io.*; +yWR#[`n  
import java.net.*; RZO5=L9E  
6Nt$ZYS  
[Uli>/%JB  
public class FileSplitterFetch extends Thread { TFy7HX\Oq  
F6W}mMZH/N  
YUscz!rM  
String sURL; //File URL 2zK"*7b?  
long nStartPos; //File Snippet Start Position &x0C4Kh  
long nEndPos; //File Snippet End Position 9cQ_mgch  
int nThreadID; //Thread's ID G;TsMq  
boolean bDownOver = false; //Downing is over $}R$t-  
boolean bStop = false; //Stop identical YsP/p-  
FileAccessI fileAccessI = null; //File Access interface !8*McO I  
Q2/.6O8  
~F w<eY  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]TSg!H  
{ m_* R.a  
this.sURL = sURL; HM&1y ubh#  
this.nStartPos = nStart; MdC<4^|  
this.nEndPos = nEnd; K;U39ofW  
nThreadID = id; /APcL5:=  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wGJjA=C  
} ,+._;[k  
5j eO"jB  
]` ]g@v  
public void run() 0@)%h&mD  
{ frN3S  
while(nStartPos < nEndPos && !bStop) Km3&N  
{ NP/>H9Q2%  
zoP%u,XL  
@Z;1 g  
try{ F Z!J  
URL url = new URL(sURL); ++8_fgM  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lJ{V  
httpConnection.setRequestProperty("User-Agent","NetFox"); 1$ML#5+,  
String sProperty = "bytes="+nStartPos+"-"; mJC3@V s  
httpConnection.setRequestProperty("RANGE",sProperty); PJgp+u<  
Utility.log(sProperty); #U=;T]!'$  
)"`!AerJ  
4:mCXP,x  
InputStream input = httpConnection.getInputStream(); |NrrTN?>  
//logResponseHead(httpConnection); <\@ 1Zz@ms  
}B q^3?,#{  
47UO*oLS  
byte[] b = new byte[1024]; f: xWu-  
int nRead; dvjTyX  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *8)2iv4[  
{ F9H~k"_ZJR  
nStartPos += fileAccessI.write(b,0,nRead); (][LQ6Pc  
//if(nThreadID == 1) a3@w|KLt  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); lj2=._@R  
} 1f4 bt6[  
;/LD)$_  
IfV  3fJ7  
Utility.log("Thread " + nThreadID + " is over!"); kWL.ewTiex  
bDownOver = true; GBP-V66  
//nPos = fileAccessI.write (b,0,nRead); ._ CP% R  
} <7n]Ai@Y  
catch(Exception e){e.printStackTrace ();} 1H{jy^sP7  
} R$m`Z+/@  
} DQJG,?e{  
&mE?y%  
](K0Fwo`;"  
//打印回应的头信息 LJQ J\bT?  
public void logResponseHead(HttpURLConnection con) Cca0](R*&  
{ 2cf' ,cv@8  
for(int i=1;;i++) 2~c~{ jl\  
{ ?Zz'|.l@  
String header=con.getHeaderFieldKey(i); [@"wd_f{l  
if(header!=null) Owf.f;QR  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )1F<6R  
Utility.log(header+" : "+con.getHeaderField(header)); naNyGE7)  
else TJy4<rb  
break; }$g mK  
} M>l^%`  
} R,Oe$J<  
{6 .o=EyM{  
\cuS>G  
public void splitterStop() x<B'.3y  
{ Vhg1/EgUr  
bStop = true; oRq!=eUu_  
} 1 W'F3  
oq;'eM1,.  
Ya Y8 `M{  
} {CUk1+  
.T.5TMiOSq  
$.K?N@(W  
/* Cg!^S(U4  
**FileAccess.java or_+2aG  
*//文件访问(定位,写) c3xl9S,5  
package NetFox; H+Z SPHs  
import java.io.*; =_pwA:z"A  
+=P@HfVfiq  
gPEqjj  
public class FileAccessI implements Serializable{ y,m2(V  
H{fM%*w  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6C-YyI#s#  
RandomAccessFile oSavedFile; 8_we: 9A  
long nPos; (P@Y36j>N  
or?%-)  
X K>&$<5{  
public FileAccessI() throws IOException :tGYs8UK  
{ 61K"(r~  
this("",0); ..KwTf  
} k#)Ad*t  
=-jD~rN4;P  
hW 2.8f$  
public FileAccessI(String sName,long nPos) throws IOException &M"ouy Zo9  
{ py<_HyJ  
oSavedFile = new RandomAccessFile(sName,"rw"); \2X$C#8E  
this.nPos = nPos; F 3RB  
oSavedFile.seek(nPos); s& yk  
} =mt?C n}  
CjL<RJR=  
BzbDZV  
public synchronized int write(byte[] b,int nStart,int nLen) ,M6ZZ* ,e  
{ 4j'd3WGpbN  
int n = -1; <$E6oZ  
try{ faJM^u  
oSavedFile.write(b,nStart,nLen); kE)!<1yy2  
n = nLen; 8{I"q[GZ  
} rT7^-B*  
catch(IOException e) Un@\kAY  
{ "{BqtU*.  
e.printStackTrace (); xJ(:m<z  
} aXR%;]<Dw  
t[C1z  
OtUr GQP  
return n; (M t5P  
} w:ULi3  
1B:aC|B  
O!R"v'  
} N:BL=} V  
Dpqt;8"2L  
2(#Ks's?  
/* Dy9\O77>  
**SiteInfoBean.java :Jxh2  
*/ $\\lx_)  
package NetFox; j, u#K)7{T  
)pgrl  
`y!/F?o+!  
public class SiteInfoBean { @h?crJ6$  
&a)vdlZSE=  
kU*{4G|6  
private String sSiteURL; //Site's URL 0Xl%uF+w  
private String sFilePath; //Saved File's Path \cySWP[  
private String sFileName; //Saved File's Name r|R7- HI  
private int nSplitter; //Count of Splited Downloading File ;4~U,+Av  
|:q/Dt@  
_PXdzeI.  
public SiteInfoBean() 3C^1f rF  
{//nSplitter的缺省值为5 FLr ;`3  
//default value of nSplitter is 5 _N#&psQzw  
this("","","",5); vK$^y^  
} 2V gP  
j F5Blc  
(.X]F_ *sc  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,E*R,'w   
{ le .'pP@  
sSiteURL= sURL; k`YYZt]@  
sFilePath = sPath; ]n v( aM?d  
sFileName = sName; tS?lB05TOR  
this.nSplitter = nSpiltter; 5vOCCW  
T0e<Slo~C  
ST',4 Oph5  
} $& {IKP)u  
F]=B'ZI  
O6c\KFBSJ  
public String getSSiteURL() 4u1KF:g  
{ isK;mU?<  
return sSiteURL; ~brFo2  
} pB01J<@m  
O!F]^'!  
*"9<TSU%m  
public void setSSiteURL(String value) _%pAlo_6  
{ 4<v;1   
sSiteURL = value; u<Xog$esu  
} 's%q  
_m'ysCjA  
fE;Q:# Z.  
public String getSFilePath() 8A2 z 5Aa  
{ "> 90E^  
return sFilePath; t1i(;|8|  
} cf;Ht^M\  
AtHS@p  
uofLhy!  
public void setSFilePath(String value) f(Hu {c5yV  
{ h4`9Cfrq,  
sFilePath = value; tYe:z:7l?<  
} !]b@RUU  
L* |1/  
$@uU@fLB  
public String getSFileName() +;gsRhWk  
{ ?pwE0N^  
return sFileName; ?0vNEz[  
} AU{:;%.g  
?U9/fl  
lOerrP6f(  
public void setSFileName(String value) bhg}-dto  
{ 2{o10 eL  
sFileName = value; z hsx &  
} `deY i2z  
R]L2(' B  
e!0OW7 kV  
public int getNSplitter() r6Nm!Bq7  
{ r"_Y3SxxL  
return nSplitter; l5 J.A@0  
} 8LrK94  
i0Pn Z J  
|B[eJq  
public void setNSplitter(int nCount) ( $d4:Ww  
{ \ P/W8{  
nSplitter = nCount; ; B$ *)X9  
} L.)yXuo4  
} >)c9|e=8  
d-$_|G+  
]+%=@mWYs  
/* 77aX-e*=E  
**Utility.java +{-]P\oc  
*/ F)ci9-b@  
package NetFox; VifmZ;S@Y  
MOHHZApt  
J r*"V`  
public class Utility { A 7Y_HIo  
gGfq6{9g  
=/Juh7[C  
public Utility() uqZ3Hyb  
{ ^gg!Me  
E(Gr0#8  
eyB_l.U7  
} {LB`)Kuu  
buY D l  
//线程睡眠 x_:hii?6V  
public static void sleep(int nSecond) nVOqn\m-  
{ v33T @  
try{ J(9=T<%T  
Thread.sleep(nSecond); p_6P`Yx^e  
} kL;t8{n  
catch(Exception e) {ymb\$f  
{ r{ @ `o@q  
e.printStackTrace (); (%DRt4u <H  
} =K'L|QKF  
} s[V `e2O  
l,y^HTc}7/  
//日志 <\D Uo0]J  
public static void log(String sMsg) GOr}/y;  
{ VGJDqm!  
System.err.println(sMsg); _rjBc ;a  
} %b<%w    
Zi1YZxF`Y  
AbY;H  
public static void log(int sMsg) a4by^   
{ SIv[9G6  
System.err.println(sMsg); V9{B}5KC  
} t2.juoI(  
} #313 (PWH  
JtmQzr0>  
?>?ZAr  
/* _85E=  
**TestMethod.java 3yMt1 fy  
*/ 2np-Fc{S  
package NetFox; <^sAY P|  
l $Zs~@N  
J/7 u7_  
public class TestMethod { M?hFCt3Y  
<2)v9c  
Y6;@/[_  
public TestMethod() cVg$dt  
{ ///xx/weblogic60b2_win.exe =,E'~P  
try{ a71}y;W  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); me$$he  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q9q9<J7j$  
SiteFileFetch fileFetch = new SiteFileFetch(bean); FB!z#Eim  
fileFetch.start(); va+m9R0  
} =n)#!i  
catch(Exception e){e.printStackTrace ();} rgn|24x  
h7RD `k:mF  
P^;WB*V  
} Z@nmjji  
n}5x-SxS0  
_w%s(dzk  
public static void main(String[] args) I,9~*^$  
{ !vrnoFVu  
new TestMethod(); VY{,x;O`  
} nOr"K;C  
} -;S3|  
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