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
  • 7575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
/* G7%bY  
**SiteFileFetch.java eVXXn)>  
*/ g52a vG  
package NetFox; ^#/FkEt7bp  
import java.io.*; %MHb  
import java.net.*; U&5* >fd=  
#.Rn6|V/4  
XjX  
public class SiteFileFetch extends Thread { l:85 _E  
/(N/DMl[  
V>{< pS  
SiteInfoBean siteInfoBean = null; //文件信息Bean t[^$F,  
long[] nStartPos; //开始位置 ~3&{`9Y  
long[] nEndPos; //结束位置 *3GV9'-P  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 ~4~`bT9  
long nFileLength; //文件长度 yYG<tUG;  
boolean bFirst = true; //是否第一次取文件 .w2ID  
boolean bStop = false; //停止标志 .Mt3e c<  
File tmpFile; //文件下载的临时信息 TktH28tK  
DataOutputStream output; //输出到文件的输出流 }r,\0Wm  
E[H  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) zKJ2 ~=  
public SiteFileFetch(SiteInfoBean bean) throws IOException .|UQ)J?s  
{ Z~5) )5Ye;  
siteInfoBean = bean; xUo6~9s7  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); m~=~DMj  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); gAqK)@8-  
if(tmpFile.exists ()) ?e7]U*jEU  
{ a)qan  
bFirst = false; 6  63o  
read_nPos();  T{YZ`[  
} J$dwy$n  
else kxn&f(5  
{ }Mc b\+[  
nStartPos = new long[bean.getNSplitter()]; UtZ,q!sg  
nEndPos = new long[bean.getNSplitter()]; j)A#}4jd  
} {1W:@6tl  
w0pMH p'Y  
WyL+HB}  
zG!nqSDG  
} TCtZ2 <'  
%bW_,b  
{zdMmpQF  
public void run() c'2d+*[  
{ u;#]eUk9}  
//获得文件长度 !rvEo =^  
//分割文件 9"[;ld<  
//实例FileSplitterFetch v9*m0|T0M  
//启动FileSplitterFetch线程 @-N` W9  
//等待子线程返回 e[S`Dm"i)'  
try{ I2cz:U7  
if(bFirst) 2-&EkF4p'  
{ .KsR48g8  
nFileLength = getFileSize(); wj|Zn+{"nF  
if(nFileLength == -1) Vz{+3vfra6  
{ ]Bw0Qq F#  
System.err.println("File Length is not known!"); sDY~jP[Oa  
} :6^7l/p  
else if(nFileLength == -2) ?$r`T]>`2  
{ J=4>zQLW  
System.err.println("File is not access!"); PNU(;&2<  
} E-e(K8R  
else $6hPTc<C  
{ {Kz,_bo  
for(int i=0;i<nStartPos.length;i++) -%K!Ra\W  
{ e#eVc'=cDR  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); x&}]8S)  
} !40>LpL[  
for(int i=0;i<nEndPos.length-1;i++) /zn=AAYb  
{ d[ N1zQW  
nEndPos = nStartPos[i+1]; L * n K> +  
} \bA Yic  
nEndPos[nEndPos.length-1] = nFileLength; hlTbCl  
} 2z.ot'  
} Hvl n>x@  
Wboh2:TH:  
k4TWfl^}9  
//启动子线程 D:)Wr, 26  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cs9^&N:w[  
for(int i=0;i<nStartPos.length;i++) JTlk[ c  
{ @ [$_cGR7  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {7o#Ve  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ab0 Sx  
nStartPos,nEndPos,i); gT+/nSrLV  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); enoj4g7em^  
fileSplitterFetch.start(); i;[y!U  
} a QH6akH  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gr=h!'m  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %x)b Z=An  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", M[uWX=  
nEndPos = " + nFileLength); z\YIwrq3*  
// fileSplitterFetch[nPos.length-1].start(); +^)v"@,VP  
oFY!NMq}:  
ON?Y Df  
//等待子线程结束 ;"3B,Yj  
//int count = 0; jYsAL=oh,*  
//是否结束while循环 D}-.<  
boolean breakWhile = false; XQ}Zr/f6  
Fsx?(?tCMo  
|(7}0]BP0  
while(!bStop) xQy,1f3s+  
{ tAX* CMW  
write_nPos(); 'J|2c;M\x  
Utility.sleep(500); B.z$0=b  
breakWhile = true; %+7]/_JO&  
@KG0QHyiU  
>}5?`.K~Q*  
for(int i=0;i<nStartPos.length;i++) s -i|P  
{ xad`-vw  
if(!fileSplitterFetch.bDownOver) yPyu)  
{ NnZW@ln"|  
breakWhile = false; Bd>~F7VWs  
break; @Mk`Tl  
} [ oWkd_dK  
} Bqx5N"  
if(breakWhile) GQ_KYS{  
break; }d$-:l ,w  
L`NIYH<^  
?Ua,ba*  
//count++; Tc2.ciU  
//if(count>4) Cj5mM[:s  
// siteStop(); :<% bAn  
} t=_^$M,yr  
K^- 1M?  
w~'xZ?  
System.err.println("文件下载结束!"); f| RmAP;X,  
} *Cy54Z#  
catch(Exception e){e.printStackTrace ();} ^l &lwSRVt  
} 6( HF)z  
UD I{4+z  
n:j'0WW  
//获得文件长度 HL)!p8UHJ  
public long getFileSize() DA=!AK>  
{ ~lj~]j  
int nFileLength = -1; 7y=>Wa?T[  
try{ E-LkP;  
URL url = new URL(siteInfoBean.getSSiteURL()); A_9WSXR  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f~IJ4T2#N  
httpConnection.setRequestProperty("User-Agent","NetFox"); LiJYyp  
^:nc'C gP  
-@To<<`n  
int responseCode=httpConnection.getResponseCode(); qHtQ4_Zn;  
if(responseCode>=400) .RQra+up  
{ K!|eN_1A  
processErrorCode(responseCode); lFBdiIw  
return -2; //-2 represent access is error De$AJl  
} z*@eQauA  
Dc9uq5l  
WhPP4 #  
String sHeader; A=|XlP$6  
j50vPV8m  
,GbmL8P7Y  
for(int i=1;;i++) !\4x{Wa]  
{ \Lx=iKs<  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y$'j9bUJ  
//Utility.log(in.readLine()); \ovs[&  
sHeader=httpConnection.getHeaderFieldKey(i); sqkWQ`Ur  
if(sHeader!=null) \i.]-k  
{ bzN[*X|  
if(sHeader.equals("Content-Length")) V&mkS  
{ 6Yai?*.Q  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1v@#b@NXM7  
break; k %I83,+  
} rYUIFPN  
} <T 2O^  
else ]uXJjS f  
break; 8PI%Z6  
} /A_:`MAZ  
} *A-_*A  
catch(IOException e){e.printStackTrace ();} A;AQw  
catch(Exception e){e.printStackTrace ();} %ms%0%  
.Rr^AGA4  
@@d_F<Ym[  
Utility.log(nFileLength); ]jT}]9Q$  
K3&xe(  
Om3Ayk}  
return nFileLength; IZVP-  
} i_qY=*a?y  
yT ^x0?U  
|Xt G9A>  
//保存下载信息(文件指针位置) S-t#d7'B  
private void write_nPos() 41 F;X{Br  
{ Nt>^2Mv   
try{ *s6 x  
output = new DataOutputStream(new FileOutputStream(tmpFile)); RhWQ:l]  
output.writeInt(nStartPos.length); *l5?_tF  
for(int i=0;i<nStartPos.length;i++) 7x)Pt@c  
{ ]b- 2:M  
// output.writeLong(nPos); +n^M+ea;  
output.writeLong(fileSplitterFetch.nStartPos); -()WTdIy  
output.writeLong(fileSplitterFetch.nEndPos); VL%. maj  
} :a wt7lqv  
output.close(); fCt|8,-H  
} j~v`q5X  
catch(IOException e){e.printStackTrace ();} *)m:u:   
catch(Exception e){e.printStackTrace ();} o78u>Oy  
} v9(5H Y  
^O|fw?,  
*_D/_Rp7  
//读取保存的下载信息(文件指针位置) }`R,C~-|^  
private void read_nPos() !Asncc G  
{ #XQ/y}(  
try{ w8lrpbLh  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J[lC$X[  
int nCount = input.readInt(); 'LgRdtO6  
nStartPos = new long[nCount]; 0ix(1`Z  
nEndPos = new long[nCount]; t:wBh'K~R8  
for(int i=0;i<nStartPos.length;i++) ]V"P &; m  
{ P2n8HFi  
nStartPos = input.readLong(); wFMH\a  
nEndPos = input.readLong(); `gSMb UgF  
} %q5dV<X'c  
input.close(); KL \>-  
} 99yWUC,  
catch(IOException e){e.printStackTrace ();} ]_ C"A  
catch(Exception e){e.printStackTrace ();} ]zx%"SUM  
} /2Izj/Q  
^E}?YgNp  
~'M<S=W  
private void processErrorCode(int nErrorCode) ("U<@~  
{ JrcbJt  
System.err.println("Error Code : " + nErrorCode); b1Vr>:sK47  
} 4,y7a=qf3  
f*%kHfaXgN  
Fz#@[1,  
//停止文件下载 >zJHvb)b\  
public void siteStop() U["0B8  
{ r+#{\~r7T  
bStop = true; U7WYS8  
for(int i=0;i<nStartPos.length;i++) y[N0P0r l:  
fileSplitterFetch.splitterStop(); )rEl{a  
 kN=&"  
,I"T9k-^  
} !!\}-r^y%  
} h,c*:  
//负责部分文件的抓取 @c^ Dl  
**FileSplitterFetch.java (dlp5:lQz  
*/ =p+n(C/  
package NetFox; W&5/1``u\  
_X#Rv2a  
m%0 -3c(  
import java.io.*; '0 Cp  
import java.net.*; WW:G( \`  
oC`F1!SfOO  
:#:|:q.]  
public class FileSplitterFetch extends Thread { G&S2U=KdV%  
^PEw#.WG  
K]|UdNo  
String sURL; //File URL xMr,\r'+  
long nStartPos; //File Snippet Start Position i q`}c |c  
long nEndPos; //File Snippet End Position \3hA_{ w  
int nThreadID; //Thread's ID xM%4/QE+  
boolean bDownOver = false; //Downing is over ROFZ*@CH<  
boolean bStop = false; //Stop identical cWAw-E5  
FileAccessI fileAccessI = null; //File Access interface vAX(3  
sD3ZZcy|=  
y,5qY}P+  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m* m),mZ"  
{ JP8}+  
this.sURL = sURL; l.@1]4.  
this.nStartPos = nStart; F*P0=DD  
this.nEndPos = nEnd; !<M eWo  
nThreadID = id; ?=&; A  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]FCP|Jz  
} IV,4BQ$  
%)j&/QdzF&  
\D|IN'!D  
public void run() 9rEBq&  
{ D|q~n)TW5  
while(nStartPos < nEndPos && !bStop) Z1 Nep !  
{ L('1NN 2  
`=Ip>7T&  
Vg'R=+Wb  
try{ .?{no}u.  
URL url = new URL(sURL); ~kZdep^]  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [1rQ'FBB^1  
httpConnection.setRequestProperty("User-Agent","NetFox"); &D3]O9a0;  
String sProperty = "bytes="+nStartPos+"-"; 8R*;8y_  
httpConnection.setRequestProperty("RANGE",sProperty); @bg9 }Z%\h  
Utility.log(sProperty); !@& 3q|  
h~>1 -T8  
}StzhV{GS  
InputStream input = httpConnection.getInputStream(); akvi^]x  
//logResponseHead(httpConnection); m]jA(  
EL~$7 J  
IWE([<i}i[  
byte[] b = new byte[1024]; DvH-M3  
int nRead; W_B=}lP@x  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) g@#he95 }  
{ +RJ{)Nec  
nStartPos += fileAccessI.write(b,0,nRead); 0%bCP/  
//if(nThreadID == 1) NQqw|3  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )M0`dy{1  
} 5t:Zp\$+`  
yX!fj\R  
== wX.y\.n  
Utility.log("Thread " + nThreadID + " is over!"); \dHqCQ  
bDownOver = true; !R@LC  
//nPos = fileAccessI.write (b,0,nRead); gC?}1]9c  
} e bze_:  
catch(Exception e){e.printStackTrace ();} +iC:/CJL  
} }T[ @G6#  
} kx&JY9(&#  
ins(RWO  
_%Z.Re  
//打印回应的头信息 eu5te0{G  
public void logResponseHead(HttpURLConnection con) Aits<0  
{ h@`Rk   
for(int i=1;;i++) O=A R`r#u  
{ ^t'mW;C$4  
String header=con.getHeaderFieldKey(i); eJoM4v  
if(header!=null) p -$C*0{  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z)T-<zWO;  
Utility.log(header+" : "+con.getHeaderField(header)); qy|bOl  
else cH&)Iz`f  
break; -H%v6E%yh  
} a{ST4d'T  
} (}b~}X9  
g !^N#o  
y11^q*}  
public void splitterStop() 1]If< <  
{ oEX,\@+u  
bStop = true; i~Tt\UA>  
} xCZ_x$bk  
P|Aac,nE+^  
_&, A  
} pwN2Nzski  
l`\L@~ln  
d.f0OhQ  
/* =b%f@x_U1  
**FileAccess.java s:_hsmc"  
*//文件访问(定位,写) x/<ow4C  
package NetFox; mW{;$@PLF"  
import java.io.*; N[ = I  
JA4Zg*7I  
wKpGJ& {  
public class FileAccessI implements Serializable{ i6paNHi*  
[<=RsD_q~  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !EIH"`>!  
RandomAccessFile oSavedFile; P"NI> HM  
long nPos; +jE)kaV%  
FJ84 'T\~  
3}}/,pGSc  
public FileAccessI() throws IOException eY 3:Nl^  
{ ]L~z9)  
this("",0); }4>u_)nt  
} ^x&x|ckR!  
4PVg?  
21OfTV-+3  
public FileAccessI(String sName,long nPos) throws IOException /K!)}f( 6  
{ '`upSJ;e  
oSavedFile = new RandomAccessFile(sName,"rw"); <l1/lm<#  
this.nPos = nPos; `:lcN0n  
oSavedFile.seek(nPos); TzC(YWt  
} ,P <I<QYu  
 _ %mm  
gp9O%g3'  
public synchronized int write(byte[] b,int nStart,int nLen) -}m  
{  *wJ$U  
int n = -1; (~G*' /)  
try{ @zS/J,:v}  
oSavedFile.write(b,nStart,nLen); L~ax`i1:"  
n = nLen; XF: wsC  
} [g}^{ $`  
catch(IOException e) v Z10Rb8  
{ Fe[6Y<x+:  
e.printStackTrace (); ^:?z7m  
} q2 7Ac; y  
W4 q9pHQ  
 5V<6_o  
return n; 9y\nO)\Tv  
} w8D8\`i!"  
&K]|{1+  
X:Y1g)|K  
} `_vPElQXZ#  
Vc'p+e|(  
[%>*P~6nK  
/* xF UD9TM  
**SiteInfoBean.java u&p8S#e  
*/ ^I/(9KP#  
package NetFox; -rsS_[$2  
cMi9 Z]  
`T[yyOL/  
public class SiteInfoBean { [vtDtwL  
?bd!JW bg`  
<;i&-,  
private String sSiteURL; //Site's URL Z2{$FN  
private String sFilePath; //Saved File's Path R@WW@ Of  
private String sFileName; //Saved File's Name /,7#%D  
private int nSplitter; //Count of Splited Downloading File *Iw19o-I  
Q \X_JZ  
blz#M #  
public SiteInfoBean() &h[)nD  
{//nSplitter的缺省值为5 G%gdI3h1Z  
//default value of nSplitter is 5 ;\"Nekd|  
this("","","",5); yzpa\[^  
} XXwIp-'  
sUF5Y q:9  
VII`qbxT  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P9\y~W  
{  qjfv9sU  
sSiteURL= sURL; ^ &KH|qRrO  
sFilePath = sPath; y3*IF2G  
sFileName = sName; N cHCcc  
this.nSplitter = nSpiltter; $_ $%L0)5  
#euOq  
j5Yli6r?3-  
} q&ed4{H<  
EHe-wC  
fR.raI4et  
public String getSSiteURL() nb5%a   
{ rGH7S!\AM  
return sSiteURL; 3I?yRE  
} !4F@ !.GG!  
Z[+Qf3j}o6  
,[m4+6G5  
public void setSSiteURL(String value) *=z.H  *  
{ |q o3 E  
sSiteURL = value; hQSJt[8My  
} 5}N O~Xd<  
Cyv_(Oh?dv  
'iYaA-9j  
public String getSFilePath() uJ*|SSN~  
{ YVY(uq)d  
return sFilePath; !oV'  
} LY0/\Z"N  
etW-gbr  
/C<} :R  
public void setSFilePath(String value) iEFS>kL8e  
{ cNN_KA  
sFilePath = value; AM gvk`<f  
} ;c~DBJg'|  
F7x< V=4{  
@7PE&3  
public String getSFileName() G`!;RX  
{ A&'HlI% J  
return sFileName; F0NNS!WP7^  
} DA4!-\bt@  
`~t$k7wm=  
Pb D|7IM  
public void setSFileName(String value) I^ A01\p  
{ ;rta#pRn  
sFileName = value; A%M&{S'+|X  
} = &aD!nTx  
.+AO3~Dg  
ldoN!J  
public int getNSplitter() ~w%Z Bp  
{ =TI|uD6T  
return nSplitter; eWx6$_|  
} VA'<  
bOmM~pD  
H+2J.&Ch  
public void setNSplitter(int nCount) HNoh B4vt  
{ 7]9s_13]  
nSplitter = nCount; -ap;Ul?  
} 7 -V_)FK2c  
} f4T-=` SO  
?Ve5}N  
J=]w$e ?.P  
/* =Jl1D*B*  
**Utility.java !c`Q?aGV)  
*/ 0\}j[-`pF  
package NetFox; R}+/jh2O|  
zZh`go02E  
M!6bf  
public class Utility { TbU9 < mY  
 Ez1*}  
<u($!ATb  
public Utility() 9'8oOBqm3%  
{ $X&OGTlw^  
E.% F/mM  
2Nl("e^kJr  
} yb**|[By  
d`nS0Tf'  
//线程睡眠 r@<;  
public static void sleep(int nSecond) 6nSk,yE'hE  
{ B 9Mwj:)}  
try{ $kz5)vj "  
Thread.sleep(nSecond); ~O 6~',KD  
} K6oX nz}  
catch(Exception e) @x J^JcE  
{ {:FITF3o  
e.printStackTrace (); &Y=NUDt_  
} fR[!=-6^f  
} 17Gdu[E  
S@"=,Xj M  
//日志 K ;xW/7?  
public static void log(String sMsg) sBu"$ "]  
{ hA\8&pI;  
System.err.println(sMsg); FW.dHvNX  
} Q#r 0DWo\  
/eMZTh*1P  
qiF~I0_0  
public static void log(int sMsg) t@JPnA7~  
{ ?RzT0HRd  
System.err.println(sMsg); X9gC2iSs]  
} Z "=(u wM  
} O.}gG6u5  
yEqmB4^-  
yaR;  
/* ^{K8uN7  
**TestMethod.java <d5vVn  
*/ I !<v$  
package NetFox; Qy/bzO  
c_a$g  
+l/j6)O`(m  
public class TestMethod { S'JeA>L  
KE&}*Nf[  
qtH&]Suu,  
public TestMethod() pz IMj_  
{ ///xx/weblogic60b2_win.exe yl 8v&e{  
try{ 4F4u1r+  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ` U3  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F i/G, [q  
SiteFileFetch fileFetch = new SiteFileFetch(bean); |O9=C`G_  
fileFetch.start(); U?lu@5 ^Z  
} hw'2q9J|  
catch(Exception e){e.printStackTrace ();} "qm>z@K  
mfN@tMp  
rWs5s!l,  
} KJ)&(Yx  
FVmg&[ .  
C|J1x4sb@  
public static void main(String[] args) _dBU6U:V  
{ h*9o_  
new TestMethod(); .>'Z9.Xnk  
} 9h(hx 7]  
} ?BZ][~n-Q  
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
如果您在写长篇帖子又不马上发表,建议存为草稿
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八