社区应用 最新帖子 精华区 社区服务 会员列表 统计排行 社区论坛任务 迷你宠物
  • 12061阅读
  • 0回复

http断点续传简单实现(java)

发帖
8
铜板
1641
人品值
95
贡献值
0
交易币
0
好评度
8
信誉值
0
金币
0
所在楼道
/* K3^2R-3:8  
**SiteFileFetch.java w[ngkLEA  
*/ Me>'QVr  
package NetFox; @C2<AmY9q*  
import java.io.*; E \RU[  
import java.net.*; < ]nI)W(  
2srz) xEe  
b4wJnmC8  
public class SiteFileFetch extends Thread { 7>LhXC  
J:(l&  
Cu]X &l  
SiteInfoBean siteInfoBean = null; //文件信息Bean n'H\*9t  
long[] nStartPos; //开始位置 L%"Mp(gZ  
long[] nEndPos; //结束位置 "e"`Or  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 S}/CzQ  
long nFileLength; //文件长度 ^5+-7+-S  
boolean bFirst = true; //是否第一次取文件 d?mdw ?|  
boolean bStop = false; //停止标志 j; C(:6#J  
File tmpFile; //文件下载的临时信息 Nvi14,q/  
DataOutputStream output; //输出到文件的输出流 4 C:YEX~  
Q8n?7JB  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) ~gc)Ww0(Q  
public SiteFileFetch(SiteInfoBean bean) throws IOException {~"=6iyj  
{ oCrn  
siteInfoBean = bean; +l9avy+P (  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); "n:9JqPb  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); V4H+m,R  
if(tmpFile.exists ()) k <qQ+\X  
{ MqqS3   
bFirst = false; a#1X)ot  
read_nPos(); h:;~)={"X  
} Ub$$wOsf  
else u@HP@>V  
{ vIJdl2(^E  
nStartPos = new long[bean.getNSplitter()]; -*EJj>x  
nEndPos = new long[bean.getNSplitter()]; `@&qf}`  
} N%a[Y  
@&+ 1b=  
<3bh-)  
~"N]%Cu  
} 2gGJ:,RC$  
{e^llfj$#  
U uys G\  
public void run() ;,1i,?  
{ k|V{jB G"@  
//获得文件长度 5c#L6 dA)  
//分割文件 b} *cw2  
//实例FileSplitterFetch k[p  
//启动FileSplitterFetch线程 F-Ea85/K@4  
//等待子线程返回 ;H^!yj5H  
try{ 7\xa_nrI  
if(bFirst) $I9zJ"*  
{ HUJ $e2[  
nFileLength = getFileSize(); yZ{YIy~  
if(nFileLength == -1) 7~',q"4P/_  
{ }?JO[Q +  
System.err.println("File Length is not known!"); Q pX@;j  
} rcK*",>  
else if(nFileLength == -2) }Z6/b _kV  
{ r\] WDX!`  
System.err.println("File is not access!"); Z Uh<2F  
} 4u&doSXR  
else 4aRYz\yT=  
{ BhKxI  
for(int i=0;i<nStartPos.length;i++) bk<3oI  
{ mf3G$=[  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); LP~$7a  
} Rq 7ksTo  
for(int i=0;i<nEndPos.length-1;i++) 4c% :?H@2  
{ C{) )T5G  
nEndPos = nStartPos[i+1]; =mZw71,  
} DXUI/C f  
nEndPos[nEndPos.length-1] = nFileLength; c2C8}XJ|O  
} 86_Zh5:  
} rT#QA=YB  
Q,$x6YwE  
;i]cmy  
//启动子线程 R Q 8okA  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; rLnu\X=h$  
for(int i=0;i<nStartPos.length;i++) /~yqZD<O  
{ ";~#epPkX  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), c"~TH.,d  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3FdoADe{{  
nStartPos,nEndPos,i); ZG>OT@ GA  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4MIVlg9  
fileSplitterFetch.start(); Np<Aak  
} ^Z!W3q Q  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |J\/U,nh  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B}(YD;7vJ  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FD*y[A ?  
nEndPos = " + nFileLength); >Cf`F{X' U  
// fileSplitterFetch[nPos.length-1].start(); Jx}5`{\  
Xy{b(b;9  
SbZk{lWcq  
//等待子线程结束 |qr[*c3$1  
//int count = 0; ~`BOz P  
//是否结束while循环 6Z"%vrH  
boolean breakWhile = false; +)|2$$m  
{p-%\nOC  
X;1q1X)K  
while(!bStop) ;2iZX=P`n  
{ TnG"_VK9R  
write_nPos(); vfjIpg%i  
Utility.sleep(500); L?P8/]DGp  
breakWhile = true; UYPBKf]A9  
MMf6QxYf  
\DHCf 4,  
for(int i=0;i<nStartPos.length;i++) =nsY[ s<  
{ <7p2OPD  
if(!fileSplitterFetch.bDownOver) \yy!?UlaI  
{ YZk&'w  
breakWhile = false; rf~Ss<  
break; h<j04fj  
} _CZ*z  
} t5_`q(:  
if(breakWhile) ;?&;I!  
break; 'W#<8eJo  
l]ZUKy  
Z(.Tl M2h  
//count++; d/^^8XUK  
//if(count>4) VTHDGBU  
// siteStop(); -or9!:8  
} R%Z} J R.  
wOsr#t7  
[9L(4F20  
System.err.println("文件下载结束!"); Q.fBuF  
} ^_oLhNoez2  
catch(Exception e){e.printStackTrace ();} ;A C] *  
} LJ)3!Q/:  
bcZuV5F&  
`i{:mio  
//获得文件长度 Bj2rA.M  
public long getFileSize() ?{[H+hzz0  
{ 6!'yU=Z`  
int nFileLength = -1; :eO]65N  
try{ }}]Y mf  
URL url = new URL(siteInfoBean.getSSiteURL()); P8EGd}2{8  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mZ5UaSG  
httpConnection.setRequestProperty("User-Agent","NetFox"); rS jC/O&b  
ug{F?LW[  
)uaB^L1  
int responseCode=httpConnection.getResponseCode(); ux }DWrR  
if(responseCode>=400) dlU=k9N-  
{ UX0tI0.tg  
processErrorCode(responseCode); 936t6K&  
return -2; //-2 represent access is error gK>Vm9rO  
} ~}5(J,1!  
wHCsEp(  
ufo?ZFq@$L  
String sHeader; ' ZJ6p0  
u+V;r)J{  
<(iOzn  
for(int i=1;;i++) #:yZJS9f9  
{ nO/5X>A,Zw  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (tz! "K  
//Utility.log(in.readLine()); kju:/kYA  
sHeader=httpConnection.getHeaderFieldKey(i); MhsG9q_%  
if(sHeader!=null) 3aOFpCs|#  
{ oM VJ+#[x  
if(sHeader.equals("Content-Length")) k.0C*3'  
{ ( u _ sz  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )CB?gW  
break; u-W=~EO5#  
} $D89|sy  
} HaSH0eTw  
else &>/nYvuq-  
break; 3S9~rLrn?  
} 8}0 D?  
} "~ `-Jkm   
catch(IOException e){e.printStackTrace ();} fG{oi(T  
catch(Exception e){e.printStackTrace ();} 07#!b~N  
:Y'nye3:  
p[wjHfIq  
Utility.log(nFileLength); 3ty){#:  
5|b/G  
w.3R1}R  
return nFileLength; \<8!b {F  
} #=tWCxf=  
Z\Q7#dl  
@Q^;qMy  
//保存下载信息(文件指针位置) @4|/| !  
private void write_nPos() pr?/rXw  
{ "gO5dZ\0  
try{ f6#H@ X  
output = new DataOutputStream(new FileOutputStream(tmpFile)); p<jr&zVEc>  
output.writeInt(nStartPos.length); UOu&sg*o2B  
for(int i=0;i<nStartPos.length;i++) OU+*@2")t  
{ J0K"WmW  
// output.writeLong(nPos); H0HYb\TX?  
output.writeLong(fileSplitterFetch.nStartPos); 1Y`MJ \9  
output.writeLong(fileSplitterFetch.nEndPos); Ob+&!XTp?0  
} 9f @)EKBK  
output.close(); vuAjAeKm  
} /?GBp[(0  
catch(IOException e){e.printStackTrace ();} G pd:k  
catch(Exception e){e.printStackTrace ();} ;CW$/^QNr5  
} )Ga6O2:  
|j+~Td3})&  
ieI-_]|[  
//读取保存的下载信息(文件指针位置) YU`{  
private void read_nPos() YszhoHYh  
{ :Ls36E8f=  
try{ &td#m"wI  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EAfSbK3z  
int nCount = input.readInt(); u|ZO"t  
nStartPos = new long[nCount]; {)y4Qp  
nEndPos = new long[nCount]; _H,RcpyJ  
for(int i=0;i<nStartPos.length;i++) )t4C*+9<U  
{ phdN9<Z  
nStartPos = input.readLong(); c1^3lgPv  
nEndPos = input.readLong(); p c],H  
} $CmTsnR1#y  
input.close(); (07d0<<[  
} #&Ee5xM=  
catch(IOException e){e.printStackTrace ();} ,Tx8^|b#F  
catch(Exception e){e.printStackTrace ();} K+\hv~+@  
} Ixw,$%-]y6  
;1%a:#5  
)&9RoW()?  
private void processErrorCode(int nErrorCode) .EdV36$n  
{ _=MWt_A '3  
System.err.println("Error Code : " + nErrorCode); H,}?YW  
} wB^a1=C  
I?"5i8E  
9V&LJhDQ  
//停止文件下载 N9Ml&*%oX{  
public void siteStop() Ua]zTMI  
{ sF$m?/Kt  
bStop = true; D4\I;M^  
for(int i=0;i<nStartPos.length;i++) ]Oy<zU  
fileSplitterFetch.splitterStop(); -O5m@rwt<  
KkY22_{ac  
R4/@dA0  
} Ir'f((8:  
} (0+m&, z  
//负责部分文件的抓取 a|NU)mgEI  
**FileSplitterFetch.java iCS/~[  
*/ H]e 2d|  
package NetFox; riL!]'akV  
|#wz)=mD  
0 Yp;?p^  
import java.io.*; A@ME7^w7  
import java.net.*; D\R^*k@V  
sn( }5;  
N;HvB:c  
public class FileSplitterFetch extends Thread { Ce:ds%  
0u_'(Z-^2  
gUp0RPs  
String sURL; //File URL `Nn?G  
long nStartPos; //File Snippet Start Position 7r>W r#  
long nEndPos; //File Snippet End Position DFonK{  
int nThreadID; //Thread's ID Z ux2VepT  
boolean bDownOver = false; //Downing is over U~m.I  
boolean bStop = false; //Stop identical zMKL: Um"  
FileAccessI fileAccessI = null; //File Access interface #7=LI\  
St`m52V(5X  
YLGLr @:q  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q)>'fZ)  
{ H<;j&\$q  
this.sURL = sURL; yH^*Fp8V  
this.nStartPos = nStart; -+> am?  
this.nEndPos = nEnd; u i1m+  
nThreadID = id; RHbwq]  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 bed+Ur&  
} t3G'x1  
UZra'+Wb  
$w\, ."y  
public void run() In&vh9Lw  
{ m##=iB|;  
while(nStartPos < nEndPos && !bStop) 9:o3JGHSc  
{ B*IDx`^Y  
H[ q{R  
;^]A@WN6_  
try{ =HHg:"  
URL url = new URL(sURL); Ne 4*MwK  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); v%5(-  
httpConnection.setRequestProperty("User-Agent","NetFox"); (#]KjpIK  
String sProperty = "bytes="+nStartPos+"-"; 3)Y:c2  
httpConnection.setRequestProperty("RANGE",sProperty); <.ky1aex7  
Utility.log(sProperty);  Dfia=1A  
Fev3CV$  
T#7^6Ks+1  
InputStream input = httpConnection.getInputStream(); L ]c9  
//logResponseHead(httpConnection); S)yV51^B  
]||=<!^kn  
mI#; pO2  
byte[] b = new byte[1024]; ]6 wi  
int nRead; !`lqWO_/ :  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) T*yveo &j  
{ 3G^Ed)JvE  
nStartPos += fileAccessI.write(b,0,nRead); *.g?y6d  
//if(nThreadID == 1) dL(|Y{4  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); R:N-y."La.  
} +ctv]'P_  
[[Z>(d$8  
`x)bw  
Utility.log("Thread " + nThreadID + " is over!"); sdQv:nd'R  
bDownOver = true; 1#"Q' ,7  
//nPos = fileAccessI.write (b,0,nRead); J B@VP{  
} W?-BT >#s  
catch(Exception e){e.printStackTrace ();} "M^W:4_  
} J-F_XKqH  
} kB#vh  
"6Uj:9  
+;;%Atgn  
//打印回应的头信息 }8 _9V|E  
public void logResponseHead(HttpURLConnection con) J_ |x^  
{ (B<AK4G  
for(int i=1;;i++) KTt$Pt/.  
{ 79H+~1Az  
String header=con.getHeaderFieldKey(i); (14kR  
if(header!=null) ;NE/!!  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); &Q>'U6"%  
Utility.log(header+" : "+con.getHeaderField(header)); nD\os[ 3  
else T0%TeFY  
break; J|S^K kC  
} 2j1v.%  
} 3ohcHQ/a  
r:4IKuTR  
E2'e}RQ  
public void splitterStop() Tj5@OcA$  
{ J5_Y\@  
bStop = true; N'P,QiR,z<  
} .+}o'rU  
!!%[JR)cS  
Wy*7jB  
} kTW g31]~  
v qMk)htIz  
5KE%@,k k  
/* :iB%JY Ad  
**FileAccess.java k^c=y<I  
*//文件访问(定位,写) :b*`hWnQ  
package NetFox; Z[u,1l.T  
import java.io.*; fMPq  
Q0Qm0B5eY  
Mk/!,N<h#  
public class FileAccessI implements Serializable{ `sy &dyM  
)=nPM`Jn.  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !r obau7  
RandomAccessFile oSavedFile; E(kpK5h{  
long nPos; SoU'r]k1x  
<<5 :zlb  
^@L l(?  
public FileAccessI() throws IOException (Zg'pSs)  
{ y6jmn1K  
this("",0); gzCMJ<3!D  
} I S8nvx\  
u;ooDIq@  
Bye@5D  
public FileAccessI(String sName,long nPos) throws IOException }"B? 8T@_~  
{ tW"ptU^9)  
oSavedFile = new RandomAccessFile(sName,"rw"); 1idjX"'  
this.nPos = nPos; CU1\C*  
oSavedFile.seek(nPos); }_(^/pnk  
} iz>y u[|  
.L5*E(<K0  
G4%M$LJ h  
public synchronized int write(byte[] b,int nStart,int nLen) m4SXH> o  
{ :#:O(K1PW  
int n = -1; pUMB)(<k  
try{ w+q;dc8  
oSavedFile.write(b,nStart,nLen); agm5D/H]:  
n = nLen; 0!,gT H>  
} &xuwke:[  
catch(IOException e) 6Y_O^f  
{ -b\ V(@5  
e.printStackTrace (); 3p 1EScH  
} 6(^Upk=59  
)):22}I#  
GHC?Tp   
return n; (<R\  
} |5B,cB_  
FWpN:|X BS  
4:eq{n  
} *tfDXQ^mN  
1;kG[z=A  
&#PBww  
/* pY!dG-;  
**SiteInfoBean.java |8qK%n f}  
*/ u~- fK'/!|  
package NetFox; QB3d7e)8>  
Prb_/B Dd  
t#pqXY/;D  
public class SiteInfoBean { eIUuq&(  
i=X*  
w^rb|mKo  
private String sSiteURL; //Site's URL |;U=YRi  
private String sFilePath; //Saved File's Path M`+e'vdw  
private String sFileName; //Saved File's Name k CW!m  
private int nSplitter; //Count of Splited Downloading File gUH'DS]{  
RnA&-\|*  
Bw]L2=d  
public SiteInfoBean() 9p\Hx#^  
{//nSplitter的缺省值为5 M Hnf\|DX  
//default value of nSplitter is 5 5 2@udp  
this("","","",5); mj~N]cxB  
} (\mulj  
#S53u?JV8  
xngeV_xc2  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N{ V5 D  
{ bg1"v a#2  
sSiteURL= sURL; 1; Wkt9]9  
sFilePath = sPath; ()nKug`.@  
sFileName = sName; j*H;a ?Y  
this.nSplitter = nSpiltter; \5_P5q:`  
h%1~v$W`  
FJd8s*  
} A |taP$ %  
{GQ Aa  
8>VI$   
public String getSSiteURL() [Zt# c C+  
{ >^H'ZYzw  
return sSiteURL; Cwsoz  
} Ck3QrfM  
=|gJb|?w  
3Zaq#uA  
public void setSSiteURL(String value) N0K>lL=  
{ cbh#E)[ '  
sSiteURL = value; o,CA;_  
} iFnOl*TC  
Iu-'o  
gY>;|),  
public String getSFilePath() 65waq~#  
{ uP(B<NfL:'  
return sFilePath; zr3q>]oma  
} cZaF f?]k  
A{4G@k+#d  
Mm5U`mB  
public void setSFilePath(String value) ~}$\B^z+  
{ )RA\kZ"  
sFilePath = value; 2Ft8dfdm`  
} k(-Z@   
CQBT::  
C7b 5%a!  
public String getSFileName() 95$pG/o  
{ 6^] `-4*W  
return sFileName; @Xq&t}*8  
} "M9TB. O  
V~J*49t&2J  
l$qStL*8O  
public void setSFileName(String value) YeRcf`  
{ .K|P&  
sFileName = value; BN\fv,  
} i>tW|N  
~']&.  
a9D gy_!Y  
public int getNSplitter() VMxYZkMNd_  
{ C!ZI&cD9  
return nSplitter; tp1KP/2w[  
} (XbMrPKG  
FylWbQU9  
hF7V !*5  
public void setNSplitter(int nCount) G}=`VYK  
{ CdBthOPX)  
nSplitter = nCount; Wj&<"Z6'm(  
} k_*XJ<S!Y  
} VO. -.  
b?Cmc  
2!{_/@I\Y  
/* 'GV&]   
**Utility.java ER~T'-YMS  
*/ E6'8Zb  
package NetFox; 3AdP^B<  
x1 ;rb8  
&5kZ{,-eM  
public class Utility { @9_nwf~X4  
q4sl=`L5Sp  
lSn5=^]q  
public Utility() ~a'nHy1  
{ lq>*x=<  
e Z@Gu  
O%YjWb  
} @D fkGm[%  
vQ:x% =]  
//线程睡眠 S}zC3  
public static void sleep(int nSecond) 8l U;y)Z  
{ -d|BO[4j  
try{ SW,q}-  
Thread.sleep(nSecond); Hi]vHG(  
} ojN`#%X  
catch(Exception e) ?@Z7O.u  
{ <KHv|)ak  
e.printStackTrace (); #'J~Xk   
} Qy{NS.T  
} wD<vg3e[H  
]~?S~l%  
//日志 5"1!p3`\D{  
public static void log(String sMsg) /yx=7<  
{ CCuxC9i7  
System.err.println(sMsg); Rz`@N`U  
} v\fzO#vj  
gXq!a|eH  
kk 8R  
public static void log(int sMsg) t *o7,  
{ r> Fec  
System.err.println(sMsg); Xy[}Gp  
} Z -pyFK\  
} jmRhAJV  
kj x>  
c*.G]nRc  
/* D",A$(lG  
**TestMethod.java xM%H~(  
*/ hX0RET  
package NetFox; G+ :bL S#:  
2#'rk'X,K  
VKT@2HjNT`  
public class TestMethod { V)2"l"Kt  
+7Sf8tg\  
&\&'L|0F  
public TestMethod() GMEw  
{ ///xx/weblogic60b2_win.exe `ifb<T  
try{ v]66.-  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $TR=3[j  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Bp &6x;MJf  
SiteFileFetch fileFetch = new SiteFileFetch(bean); zXQVUhL6  
fileFetch.start(); 1T!cc%ah  
} j?=VtVP  
catch(Exception e){e.printStackTrace ();} 5_v5  
)qbI{^_g  
~af8p {  
} 1lbwJVY[  
qO7fbql_  
+VwV5iy[`  
public static void main(String[] args) h{\t*U 54'  
{  W|lH   
new TestMethod(); o(:{InpV%A  
} a4%`"  
} )y6QAp  
点击下载更多相关资料
评价一下你浏览此帖子的感受

精彩

感动

搞笑

开心

愤怒

无聊

灌水
描述
快速回复

您目前还是游客,请 登录注册
如果您提交过一次失败了,可以用”恢复数据”来恢复帖子内容
认证码:
验证问题:
10+5=?,请输入中文答案:十五