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
  • 10937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
/* 'pQ\BH  
**SiteFileFetch.java wN^$8m5\T^  
*/ ZGZ+BOFL  
package NetFox; #!RO,{FT  
import java.io.*; N}5'Hk4+  
import java.net.*; VyWPg7}e  
dSq3V#Q  
]R?{9H|jwE  
public class SiteFileFetch extends Thread { {.mP e|  
p^>_VE[S  
m?)REE  
SiteInfoBean siteInfoBean = null; //文件信息Bean x_VD9  
long[] nStartPos; //开始位置 y Nc"E  
long[] nEndPos; //结束位置 14Y<-OO: k  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 @B#\3WNt  
long nFileLength; //文件长度 s. ]<r5v7  
boolean bFirst = true; //是否第一次取文件 n4%ZR~9WH  
boolean bStop = false; //停止标志 $vjl-1x&  
File tmpFile; //文件下载的临时信息 MIF`|3$,  
DataOutputStream output; //输出到文件的输出流 vA"MTncv  
D6L5X/#  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) .0]\a~x  
public SiteFileFetch(SiteInfoBean bean) throws IOException 6zR9(c:a~  
{ (RBzpAiH  
siteInfoBean = bean; ^T&@(|o  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); AAW])c`.  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); /|MHZ$Y9w?  
if(tmpFile.exists ()) LfsqtQ=J`  
{ mtd ,m  
bFirst = false; pEp`Z,p  
read_nPos(); 2*)2c[/0F  
} K~6,xZlDWM  
else rU!QXg]uD  
{ 4#"_E:;PQ  
nStartPos = new long[bean.getNSplitter()]; HY!R|  
nEndPos = new long[bean.getNSplitter()]; ky#5G-X  
} AS? ESDC  
'JK"3m}nT  
]9]o*{_+(f  
 oo4aw1d  
} :/<SJ({q  
Q}6!t$Vk  
1O,:fTG<  
public void run() oqUF_kh  
{ xmXuBp:M(R  
//获得文件长度 EJ@&vuDd$  
//分割文件 J1UG},-h  
//实例FileSplitterFetch 50jZu'z:  
//启动FileSplitterFetch线程 )Gm,%[?2C  
//等待子线程返回 $~c wB  
try{  Qo$j'|lD  
if(bFirst)  @ ^cR  
{ ?DrA@;IB  
nFileLength = getFileSize(); =8V 9E  
if(nFileLength == -1) \@!"7._=  
{ hH(w O\s  
System.err.println("File Length is not known!"); U]AJWC6  
} .$"13"  
else if(nFileLength == -2) q"9 2][}  
{ &,8F!)[9  
System.err.println("File is not access!"); H~:EPFi.(  
} N5d)&a 7?  
else gzd<D}2F~  
{ Kg6[  
for(int i=0;i<nStartPos.length;i++) e%_J O7  
{ OaeX:r+&Q  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); AEd]nVV Q  
} ?RQ_LA;  
for(int i=0;i<nEndPos.length-1;i++) |5TzRz  
{ NpLZ ,|H  
nEndPos = nStartPos[i+1]; G nPrwDB  
} m"/ o4  
nEndPos[nEndPos.length-1] = nFileLength; L.?QZN%cN  
} ;V0^uB.z  
} W"n0x8~sV  
K 7 OIT2-  
F87/p  
//启动子线程 urhOvC$a  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; A@<a')#>)  
for(int i=0;i<nStartPos.length;i++) ? FlQ\q  
{ S7 !;Z@  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), NH'Dz6K5  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zvbO q  
nStartPos,nEndPos,i); bY UG4+rD  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H@!]5 <:9  
fileSplitterFetch.start(); 6^e}^~|  
} r#'ug^^k$X  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %zz,qs)Eu  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); x/dyb.  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", eXQLE]L]  
nEndPos = " + nFileLength); |i\%> Y,  
// fileSplitterFetch[nPos.length-1].start(); BIh^b?:zU  
Mz6PH)e;  
`Kbf]"4q  
//等待子线程结束 Jo''yrJpB  
//int count = 0; Ji4JP0  
//是否结束while循环 8I[=iU7]l  
boolean breakWhile = false; Ef$a&*)PH  
FD al;T  
Ggk#>O G  
while(!bStop) `0, G' F  
{ t>! Ok  
write_nPos(); 46##(4RF  
Utility.sleep(500); tj4/x7!  
breakWhile = true; 3O*^[$vM  
&u2H^ j  
C2{*m{ D  
for(int i=0;i<nStartPos.length;i++) T5Iz{Ha  
{ p1UYkmx[  
if(!fileSplitterFetch.bDownOver) UvR.?js(O  
{ sBk|KG  
breakWhile = false; 7 !dj&?  
break; m6uFmU*<M}  
} *#9?9SYSk  
} [Ob09#B%:5  
if(breakWhile) Ggry,3X3  
break; =P%?{7  
;pj,U!{%s\  
-}u1ZEND  
//count++; " GY3sam  
//if(count>4) !bs5w_@  
// siteStop(); mw&'@M_(7  
} {T-=&%||  
x[=,$;o+  
3Cgv($xl&  
System.err.println("文件下载结束!"); "5204I  
} -tIye{  
catch(Exception e){e.printStackTrace ();} iPdS>e e  
} lAR1gHhJ  
Kr?<7vMT5  
~BiLzT1,  
//获得文件长度 Gz52^O :  
public long getFileSize() iG#9 2e4  
{ ,FwpHs $A  
int nFileLength = -1; (8baa.ge  
try{ #(QS5J&Qq  
URL url = new URL(siteInfoBean.getSSiteURL()); +Sc2'z>R  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); NL,6<ZOon,  
httpConnection.setRequestProperty("User-Agent","NetFox"); _Q'f^Kj  
0avtfQ +f  
w75Ro6y  
int responseCode=httpConnection.getResponseCode(); 10Q!-K),p  
if(responseCode>=400) IrUoAQ2xpG  
{ V?)YQ B  
processErrorCode(responseCode); eX1_=?$1P  
return -2; //-2 represent access is error +|Izjx]ZV  
} `A9fanh  
*{,}pK2*  
X .sOZb?$  
String sHeader; Z;S)GUG^  
eLLOE)x  
;l^'g}dQ^  
for(int i=1;;i++) 4V c``Um  
{ O`$\P lt|v  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +koW3>  
//Utility.log(in.readLine()); >{l b|Vx  
sHeader=httpConnection.getHeaderFieldKey(i); KrR`A(=WL  
if(sHeader!=null) LP !d|X  
{ - (7oFOtg  
if(sHeader.equals("Content-Length")) m%'T90mi  
{ :|8!w  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Apj[z2nr  
break; [nG[ x|;|  
} ?9%$g?3Z  
} Tq SjL{l%  
else X#Ob^E%J  
break; Qsw.429t  
} VCVKh  
} \TYVAt] ?  
catch(IOException e){e.printStackTrace ();} 6J_$dzw  
catch(Exception e){e.printStackTrace ();} I2krxLPd  
0dQ\Y]b  
Z?d][zGw  
Utility.log(nFileLength); c[T@lz(!  
cltx(C>   
qA[cF$CIl)  
return nFileLength; EG|_YW7  
} Q+/P>5O/  
x0%yz+i{:  
$d,/(*Y#-  
//保存下载信息(文件指针位置) pFV~1W:  
private void write_nPos() uH(M@7"6_!  
{ |Qb@.  
try{ xj9xUun  
output = new DataOutputStream(new FileOutputStream(tmpFile)); *K& $9fah  
output.writeInt(nStartPos.length); F(ZczwvR  
for(int i=0;i<nStartPos.length;i++) >^IUS8v  
{ OG_v[  C5  
// output.writeLong(nPos); y2mSPLw  
output.writeLong(fileSplitterFetch.nStartPos); F>5b[q6~4  
output.writeLong(fileSplitterFetch.nEndPos); g[HuIn/  
} ^go3F{; 4i  
output.close(); oad /xbp@/  
} $e{[fm x  
catch(IOException e){e.printStackTrace ();} 7G7"Zule*j  
catch(Exception e){e.printStackTrace ();} pe>?m^gz[  
} Jw>na _FJ  
2kk; z0f  
A`Rs n\  
//读取保存的下载信息(文件指针位置) F\v~2/J5v  
private void read_nPos() So75h*e  
{ R,BINp  
try{ h(GSM'v  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,b5vnW\  
int nCount = input.readInt(); 6'x3g2C/  
nStartPos = new long[nCount]; g3yZi7b5FU  
nEndPos = new long[nCount]; Gm3`/!r  
for(int i=0;i<nStartPos.length;i++) B#}EYY  
{ mxu!$wx  
nStartPos = input.readLong(); uHRxV"@}[1  
nEndPos = input.readLong(); "c?31$6  
} xn@oNKD0  
input.close(); g>#}(u!PH  
} | +uc;[`  
catch(IOException e){e.printStackTrace ();} th<>%e}5c  
catch(Exception e){e.printStackTrace ();} Oqt{ uTI~  
} d(@ ov^e-  
yW\kmv.O  
_3NH"o d  
private void processErrorCode(int nErrorCode) 1~},}S]id  
{ fU\;\  
System.err.println("Error Code : " + nErrorCode); ori[[~OyB  
} FQE(qltf,  
cct/mX2&~  
.6I'V3:Kg  
//停止文件下载 :h/v"2uDN  
public void siteStop() eAqpP>9n  
{ hy@b/Y![M  
bStop = true; M;NIcM  
for(int i=0;i<nStartPos.length;i++) s?&S<k-=fr  
fileSplitterFetch.splitterStop(); Xy`'h5  
R3LIN-g(  
:zvAlt'q=  
} ^<uQ9p^B  
} V]"pM]>3X  
//负责部分文件的抓取 Z }Q/u^Z  
**FileSplitterFetch.java a;nYR5f  
*/ WS?Y8~+{5  
package NetFox; ?AQA>D#W  
;Bw3@c  
^R)]_   
import java.io.*; 2$VSH&  
import java.net.*; feeHXKD|  
1'iQlnMO@  
g6S-vSX,  
public class FileSplitterFetch extends Thread { }R YPr  
-}( o+!nl  
DRTT3;,N  
String sURL; //File URL "3|OB, <;:  
long nStartPos; //File Snippet Start Position M'oZK  
long nEndPos; //File Snippet End Position NS TO\36  
int nThreadID; //Thread's ID AxF$7J(  
boolean bDownOver = false; //Downing is over oIMS >&  
boolean bStop = false; //Stop identical 1mR@Bh  
FileAccessI fileAccessI = null; //File Access interface 52,'8` ]  
6D`.v@  
Y=O-^fL  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1CM 8P3  
{ )q\6pO@  
this.sURL = sURL; KoWG:~>|  
this.nStartPos = nStart; #`l&HV   
this.nEndPos = nEnd; I3izLi  
nThreadID = id; +"JWsD(C(  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :f7vGO"t  
} iP:^nt?  
_JA)""l%  
+_gA"I  
public void run() gS`Z>+V5!c  
{ G `B=:s]  
while(nStartPos < nEndPos && !bStop) cWo__EE  
{ Y?zo")  
<Lt"e8Z>x  
rSm#/)4A  
try{ gQ%mVJB{(  
URL url = new URL(sURL); 8DbP$Wwi  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o]&P0 b  
httpConnection.setRequestProperty("User-Agent","NetFox"); 5Z"N2D)."  
String sProperty = "bytes="+nStartPos+"-"; a1[J>  
httpConnection.setRequestProperty("RANGE",sProperty); `0w!&  
Utility.log(sProperty); BQeg-M  
V`YmGo  
'aEN(Mdz1e  
InputStream input = httpConnection.getInputStream(); \_i22/Et  
//logResponseHead(httpConnection); BO6XY90(  
e 0Z2B2  
D~`RLPMk  
byte[] b = new byte[1024]; S&k/Pc  
int nRead; 0AoWw-H6V  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) MBU4Awj  
{ No+BS%F5  
nStartPos += fileAccessI.write(b,0,nRead); dldS7Q  
//if(nThreadID == 1) nLPd]%78>  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 322-'S3<  
} w vI v+Q9  
ed3wj3@  
%\)AT"  
Utility.log("Thread " + nThreadID + " is over!"); }g|9P SbJ  
bDownOver = true; / T_v8 {D  
//nPos = fileAccessI.write (b,0,nRead); O`N,aYo  
} EaH/Gg3  
catch(Exception e){e.printStackTrace ();} [D?d~pB  
} /rK/ l  
} g0s4ZI+T  
wqap~X  
S@~ReRew2  
//打印回应的头信息 f}ch1u>  
public void logResponseHead(HttpURLConnection con) fjuPGg~  
{ *#@{&Q(Qh  
for(int i=1;;i++) ,:V[H8 ?  
{ #T`1Z"h<  
String header=con.getHeaderFieldKey(i); _G/uDP%  
if(header!=null) +@7c:CAy(  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); B)0;gWK  
Utility.log(header+" : "+con.getHeaderField(header)); ,W/Y@ScC  
else |S]fs9  
break; 73{<;z}i  
} b.}J'?yLm  
} Eq=JmO'gHs  
Bi"cWO  
e ^`La*n  
public void splitterStop() 8vfC  
{ }>3jHWxLc  
bStop = true; at2)%V)  
} ?nE9@G5Gc  
_(8N*q*w  
RmO kb~  
} uBC#4cX`D*  
1Vz3N/AP%?  
{?A/1q4rr  
/* 8)83j6VF  
**FileAccess.java /;u=#qu(E-  
*//文件访问(定位,写) ') 2LP;(  
package NetFox; q%)."10}]  
import java.io.*; ltkA7dUbu  
e<~bDFH  
%/!f^PIwX  
public class FileAccessI implements Serializable{ 9 OlJC[  
?/~Q9My  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8k.#4}fP  
RandomAccessFile oSavedFile; "tDB[?  
long nPos; r $YEq5  
)2u_c=  
UjyrmQf  
public FileAccessI() throws IOException 9PaV*S(\TR  
{ , 0?_? GO  
this("",0); ]IDhE{  
} V~Jt  
Tq6\oIBkV  
e#WASHZN  
public FileAccessI(String sName,long nPos) throws IOException OL@$RTh  
{ {"rL3Lk  
oSavedFile = new RandomAccessFile(sName,"rw"); @f,/K1k  
this.nPos = nPos; )U8=-_m  
oSavedFile.seek(nPos); ZK<c(,oZ^  
} 5 (q4o`  
ogV v 8Xb  
|F qujZz  
public synchronized int write(byte[] b,int nStart,int nLen) ?d k)2  
{ |ss4pN0X  
int n = -1; [EQTrr( D  
try{ rV*Ri~Vx  
oSavedFile.write(b,nStart,nLen); `?d` #) Ck  
n = nLen; ?-<>he  
} SF"r</c[  
catch(IOException e) R#rfnP >  
{ 5E}]U,$  
e.printStackTrace (); bJynUZ  
}  DD[<J:6  
I-Am9\   
w.+G+ r=  
return n; ~{{7y]3M-  
} S&Hgr_/}c  
gTd r  
h66mzV:`  
} _d>{Hz2  
n9Vr*RKM)  
`y{[e j  
/* `@So6%3Y|  
**SiteInfoBean.java /7ykmW  
*/ z.tN<P7  
package NetFox; ke2M&TV  
UunZ/A$]m  
w ,0OO f  
public class SiteInfoBean { V~$?]Z%_  
tK 6=F63e  
:g+ wv}z  
private String sSiteURL; //Site's URL MaF4lFmS  
private String sFilePath; //Saved File's Path CWb*bw0  
private String sFileName; //Saved File's Name /HdjPxH  
private int nSplitter; //Count of Splited Downloading File ^#4<~zU  
on1B~?*D  
*{O[}  
public SiteInfoBean() :+8qtIytKX  
{//nSplitter的缺省值为5 {?r5~ T`2  
//default value of nSplitter is 5 Sj v iH  
this("","","",5);  e `K{  
} +{%)}?F  
6yC4rX!a  
\]3[Xw-$  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Lx| 0G $  
{ .F/s (  
sSiteURL= sURL; %kP=VUXj  
sFilePath = sPath; F><ficT  
sFileName = sName; CbOCL~ "  
this.nSplitter = nSpiltter; Ian+0 ?`e  
yIWgC[  
w/9%C(w6  
} K.b :ae^k  
8KsPAK_  
NC sem  
public String getSSiteURL() #1WCSLvtV  
{ Q9&H/]"v  
return sSiteURL; fGWXUJ  
} ~{pds  
"kjSg7m*:  
l]~IZTC  
public void setSSiteURL(String value) }q,dJE  
{ z:&/O&?  
sSiteURL = value; xrv0%  
} fT YlIT9  
hUEA)c  
Mt@Ma ]!  
public String getSFilePath() WYIv&h<h"  
{ +fQJ#?N2n  
return sFilePath; dZ4c!3'F  
} Q 87'zf  
T9Fe!yVA  
,}NTV ~  
public void setSFilePath(String value) -wh  
{ Zg|l:^E  
sFilePath = value; DHZ`y[&}|N  
} x~](d8*=  
F 1l8jB\  
W>'(MB$3  
public String getSFileName() QZuKM'D+  
{ h05<1>?|  
return sFileName; 20I/En  
} e`Co ='  
Of}C.N8  
?P/73p  
public void setSFileName(String value) 7R5+Q\W  
{ 1\g r ;b  
sFileName = value; 5<P6PHdY  
} *U`R<mV\  
AS'+p%(  
8is QL  
public int getNSplitter() bCiyz+VyJn  
{ yet ~  
return nSplitter; yD@1H(yM  
} 69`*u<{PC  
)"7z'ar  
d\25  
public void setNSplitter(int nCount) l(\F2_,2W  
{ ?-tNRIPW@p  
nSplitter = nCount; D  ,[yx='  
} /QQjb4S}  
} [X*u`J  
bD-OEB  
B>@l(e)b  
/* k$>5v +r0  
**Utility.java qd<I;*WV  
*/ `Jh<8~1  
package NetFox; _(I)C`8m  
L~RFI&b  
c0;rvw7  
public class Utility { ^F&j;8U  
z[y  
v8n^~=SH  
public Utility() amQTPNI  
{ n~0MhE0H  
}_('3C,Ba  
&(e5*Q  
} cwzgIm+  
C>SO d]  
//线程睡眠 ^'fgQyj  
public static void sleep(int nSecond) A 6 `a  
{ Y?L>KiM$  
try{ {|B[[W\TN  
Thread.sleep(nSecond); O0 $V+fE  
} T\bpeky~  
catch(Exception e) 2'-84  
{ |sEuhP\A3  
e.printStackTrace (); F!p;]B  
} cDK)zD  
} Vhr6bu]  
UcH#J &r  
//日志 N(2M  w:}  
public static void log(String sMsg) ]&dPY[~,/i  
{ ;>S|?M4GZ  
System.err.println(sMsg); Q7i(M >|O  
} be$']}cP  
9A/bA|$  
&I%E8E  
public static void log(int sMsg) *LuR o  
{ 4C ;y2`C  
System.err.println(sMsg); 9,JWi{lIv  
} Et0)6^-v  
} +L@\/=;G  
L27WDm^)  
) .KMZ]  
/* `zB bB^\`W  
**TestMethod.java /)kx`G_  
*/ PB!XApTb  
package NetFox; y,bD i9*|  
vVrM[0*c  
{m@tt{%  
public class TestMethod { o8v,17 8  
dCo3VF"u  
Dwr 9}Z-]  
public TestMethod() 3s67)n  
{ ///xx/weblogic60b2_win.exe <]X 6%LX  
try{ +S`cUn7  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); L ./c#b!{  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g-1j#V`5  
SiteFileFetch fileFetch = new SiteFileFetch(bean); X$6QQnyR  
fileFetch.start(); [J(b"c6  
} cbs ;  
catch(Exception e){e.printStackTrace ();} adAdX;@e`  
$R NHRA.  
+\)Y,@cw  
} vU]n0)<KB  
@LSh=o+  
u[oV Jvc  
public static void main(String[] args) #dD0vYT&od  
{ ~*9Ue@  
new TestMethod(); hJD3G |E  
} o)]O  
} 3^xq+{\)  
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
欢迎提供真实交流,考虑发帖者的感受
认证码:
验证问题:
10+5=?,请输入中文答案:十五