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
  • 11657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
/* d}.*hgk  
**SiteFileFetch.java ^at X/  
*/ cN5,\I.  
package NetFox; 9y~5@/3 2R  
import java.io.*; nKzS2 u=:Y  
import java.net.*; @,Iyn<v{B  
`bJ+r)+5  
#Wz7ju;  
public class SiteFileFetch extends Thread { w)hH8jx{  
8"zFTP*;u  
EC4RA'Bg1k  
SiteInfoBean siteInfoBean = null; //文件信息Bean .qcIl)3  
long[] nStartPos; //开始位置 POtj6 ?a  
long[] nEndPos; //结束位置 Oz[]]`C1  
FileSplitterFetch[] fileSplitterFetch; //子线程对象  jx3J$5  
long nFileLength; //文件长度 cBO.96ZHE  
boolean bFirst = true; //是否第一次取文件 &pCNOHi|  
boolean bStop = false; //停止标志  6tPgFa#N  
File tmpFile; //文件下载的临时信息 XPhC*r  
DataOutputStream output; //输出到文件的输出流 )r)3.|wJm  
s 9Y'MQo*  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) /2!Wy6 p  
public SiteFileFetch(SiteInfoBean bean) throws IOException o-))R| ~z  
{ 8 pQx6QE  
siteInfoBean = bean; OUd&fUmH  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); QD6in>+B@  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); (Mk9##R#  
if(tmpFile.exists ()) |Mj2lZS  
{ (W~')A"hC'  
bFirst = false; \D9J!K82  
read_nPos(); ld-Cb 3R^  
} c?;YufH'j  
else '9+JaB  
{ }J~ d6m  
nStartPos = new long[bean.getNSplitter()]; V5MLzW\8  
nEndPos = new long[bean.getNSplitter()]; p6MjVu  
} c/G4@D>  
nNCG*Vu  
o~vUqj?BA  
H}R/_5g  
} fq@r6\TI  
DcO$&)Eb  
GI~JIXHTQ  
public void run() yZ_6yJw3}  
{ }, < dGmkx  
//获得文件长度 o1m+4.-  
//分割文件 5cv&`h8uo_  
//实例FileSplitterFetch 6%hr]>L  
//启动FileSplitterFetch线程 ]Kutuf$t  
//等待子线程返回 Y;X_E7U  
try{ 4@b~)av)  
if(bFirst) yh  
{ 0%Y8M` ~s7  
nFileLength = getFileSize(); fd{75J5%  
if(nFileLength == -1) K/Q%tr1W0  
{ ig Q,ZY1  
System.err.println("File Length is not known!"); >tmv3_<=  
} A)2eo<ij4  
else if(nFileLength == -2) (;9-8Y&_d  
{ $ ]ew<j  
System.err.println("File is not access!"); }#u.Of`6"  
} ^V1.Y  
else Oy,7>vWQI  
{ H2ZRUFu  
for(int i=0;i<nStartPos.length;i++) ;qA(!`h+  
{ Lp|7s8?  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); <|!?V"`3  
} pk%%}tP<  
for(int i=0;i<nEndPos.length-1;i++) [tKH'}/s=  
{ #-]!;sY>  
nEndPos = nStartPos[i+1]; :>:F6Db"U  
} FZt a  
nEndPos[nEndPos.length-1] = nFileLength; v%ldg833l  
} N;YAG#'9~_  
} eK=W'cNu  
Y#VtZTcT  
eWN[EJI<  
//启动子线程 GOKca%DT=  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X j>?P/=Z  
for(int i=0;i<nStartPos.length;i++) ! sN~w  
{ >@Nn_d  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m-< "`:+  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X,] E {  
nStartPos,nEndPos,i); LU-,B?1  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c:J;Q){Xz  
fileSplitterFetch.start(); '`)r<lYN,  
} T J!d 7  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A~@u#]]<n  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (~6D`g`B  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W~!uSrY  
nEndPos = " + nFileLength); U,tl)(!@Q-  
// fileSplitterFetch[nPos.length-1].start(); W Ai91K@  
O`;e^PhN  
[Yq*DkW  
//等待子线程结束 Y"n$d0%  
//int count = 0; 1edeV48{:  
//是否结束while循环 j3Sz+kOf,  
boolean breakWhile = false; 0SHF 8kek  
z]twh&^1L  
j>}<FW-N  
while(!bStop) 6h5,XcO4  
{ 0b)q,]l]  
write_nPos(); 5DI&pR1eZ  
Utility.sleep(500); <>Nq ]WqA  
breakWhile = true; >" &&,~  
mRECd Gst  
`W*b?e| H1  
for(int i=0;i<nStartPos.length;i++) N wISf  
{ i$z).S?1  
if(!fileSplitterFetch.bDownOver) hhM?I$t:  
{ /c&;WlE/n  
breakWhile = false; r(VGdG  
break; |z+K]R8_  
} sTb@nrRxH  
} oEuV&m|yX  
if(breakWhile) :L6,=#  
break; j><8V Qx  
b9%G"?~Zz  
X!AD]sK  
//count++; DNyU]+\L[l  
//if(count>4) >Oz~j>jL  
// siteStop(); ?BEO(;'  
} xoYaL  
U WU PY  
>.76<fni  
System.err.println("文件下载结束!"); smJ#.I6/L  
} eyIbjgpV  
catch(Exception e){e.printStackTrace ();} dfa^5`_  
} sN8)p%'Lg  
>T)#KQ1t  
*#| lhf'  
//获得文件长度 VGVb3@  
public long getFileSize() ImG7E w  
{ :~ ; 48m  
int nFileLength = -1; u&npUw^Va  
try{ ,K-?M5(n9  
URL url = new URL(siteInfoBean.getSSiteURL()); B7u4e8(E*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S_|VlI  
httpConnection.setRequestProperty("User-Agent","NetFox"); g{U?Y"  
1M<;}hJ{/  
B=;p wX  
int responseCode=httpConnection.getResponseCode(); )_H>d<di  
if(responseCode>=400) -Z<V? SFOK  
{ VmbfwHRWb  
processErrorCode(responseCode); "Ei' FM  
return -2; //-2 represent access is error $psPNJG  
} j +u3VP  
O ,Sqh$6U  
}%lk$g';  
String sHeader; !hc#il'g].  
l(j._j~p  
}^"#&w3<  
for(int i=1;;i++) j3$\+<m]  
{ !gX(Vh*k  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); bH1MDBb2  
//Utility.log(in.readLine()); -S6^D/(;  
sHeader=httpConnection.getHeaderFieldKey(i); }Lc8tj<  
if(sHeader!=null) ZBxV&.9/  
{ xC^|S0B  
if(sHeader.equals("Content-Length")) e{k)]]J  
{ BqG7E t  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C?-_8OA  
break; V =-hqo(  
} .cCB,re  
} tFrNnbmlQ  
else \O G`+"|L  
break; *{1]b_<  
} i^_?C5  
} .'Rz tBv  
catch(IOException e){e.printStackTrace ();} v_L?n7c  
catch(Exception e){e.printStackTrace ();} 'ngx\Lr  
7a5G,C#QQ  
UkzLUok]U  
Utility.log(nFileLength); .J fV4!=o  
(|t)MnPfY  
<HMmsw  
return nFileLength; I5H#]U  
} E7AYK&  
-s,guW |  
&O;' ?/4 S  
//保存下载信息(文件指针位置) %YV3-W8S0  
private void write_nPos() m14OPZ<3?-  
{ %5-   
try{ M?G4k]  
output = new DataOutputStream(new FileOutputStream(tmpFile)); -xMM}r y  
output.writeInt(nStartPos.length); @mRda %qR  
for(int i=0;i<nStartPos.length;i++) v#ERXIrf  
{ I?#B_R#  
// output.writeLong(nPos); GGF;4  
output.writeLong(fileSplitterFetch.nStartPos); "Wz74ble  
output.writeLong(fileSplitterFetch.nEndPos);  FtmI\,  
} H;kk:s'  
output.close(); @(I)]Ca%O  
} #1VejeTi  
catch(IOException e){e.printStackTrace ();} y>iote~  
catch(Exception e){e.printStackTrace ();} k`;&??  
} _ H$^m#h  
y1*z," dx  
GkYD:o=qx  
//读取保存的下载信息(文件指针位置) `bMwt?[*  
private void read_nPos() S/H!a:_5r  
{ 3lo.YLP^  
try{ .p?kAf`  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); )uxXG `,h  
int nCount = input.readInt(); 8Ssk>M*  
nStartPos = new long[nCount]; @$] CC1Y  
nEndPos = new long[nCount]; r}~|,O3bc'  
for(int i=0;i<nStartPos.length;i++) "Qfw)!#  
{ ]~J.YX9ST  
nStartPos = input.readLong(); Qu6Q)dZ<  
nEndPos = input.readLong(); ganXO5T$  
} !PuW6  
input.close(); \r^*4P,,  
} C$#X6Q!,  
catch(IOException e){e.printStackTrace ();} [>xGynU0  
catch(Exception e){e.printStackTrace ();} 8^)K|+_'m  
} O}cg1Q8p  
y jQpdO  
:^ *9E b  
private void processErrorCode(int nErrorCode) M-+pYv#&P  
{ n=tg{_9f%  
System.err.println("Error Code : " + nErrorCode); <'l;j"&lp  
} (14J~MDB  
-Ka0B={Z  
dd|/I1  
//停止文件下载 Mg^.~8\d e  
public void siteStop() .BqS E   
{ &Dw8GU}1  
bStop = true; ?~fuMy B  
for(int i=0;i<nStartPos.length;i++) hY^-kdQ>M  
fileSplitterFetch.splitterStop(); {nyVC%@Y  
/m+q!yi &  
E])X$:P?  
} WTZr{)e  
} }2i3  
//负责部分文件的抓取 N,Ys}qP  
**FileSplitterFetch.java "H!2{l{  
*/ =`y.L5  
package NetFox; *3r{s'm  
8jxs%N,aI  
PN @[k:5(  
import java.io.*; gt= _;KZ  
import java.net.*; fsVQZ$h73  
^7O,Vk"Z  
G: p!PB>=  
public class FileSplitterFetch extends Thread { ' *x?8-KP  
FMBzTD  
M+q|z0U  
String sURL; //File URL ~.'NG? %7P  
long nStartPos; //File Snippet Start Position 1XvB,DhJ  
long nEndPos; //File Snippet End Position ]&kzIxh  
int nThreadID; //Thread's ID _m8JU  
boolean bDownOver = false; //Downing is over 5 qW*/  
boolean bStop = false; //Stop identical TRSR5D[  
FileAccessI fileAccessI = null; //File Access interface c7$U0JO  
)/1,Ogb%_  
Z-BPC|e  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ;q6FdS  
{ B\z4o\am%  
this.sURL = sURL; #H1ng<QV  
this.nStartPos = nStart; E%E3h1Ua  
this.nEndPos = nEnd; g,seqh%  
nThreadID = id; j)[ w X  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 R9B!F{! 5  
} 3"OD"  
B U^3Ux$  
,'69RL?-Wg  
public void run() u  teI[Q  
{ (&x#VmDL  
while(nStartPos < nEndPos && !bStop) K[( h2&  
{ &v#*  
#[a+m  
8`/nk `;  
try{ (!^(74  
URL url = new URL(sURL); o]vU(j_Ju  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (8*& 42W  
httpConnection.setRequestProperty("User-Agent","NetFox"); Y"U -Rc  
String sProperty = "bytes="+nStartPos+"-"; i C nWb  
httpConnection.setRequestProperty("RANGE",sProperty); k_c8\::p#  
Utility.log(sProperty); 2Hp#~cE+.  
c%+9uu3  
fy`e)?46  
InputStream input = httpConnection.getInputStream(); ,.ln  
//logResponseHead(httpConnection); Y :0SrB!\  
z7H[\4A!>  
O)tZ`X;  
byte[] b = new byte[1024]; TCd1JF0  
int nRead; N?'V,p 0=  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) M8,W|eTM  
{ Z ?{;|Z5  
nStartPos += fileAccessI.write(b,0,nRead); b%fn1Ag9  
//if(nThreadID == 1) aiKZ$KLC  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mt+IB4`  
} 0O,l rF0'  
4ZK8Y[]Lv  
54Baz  
Utility.log("Thread " + nThreadID + " is over!"); xM/B"SG2  
bDownOver = true; i 7fQj, q  
//nPos = fileAccessI.write (b,0,nRead); [V5ebj:6w  
} Bk~lE]Q3c7  
catch(Exception e){e.printStackTrace ();} ,\|W,N}~  
} 9W{=6D86e  
} }lk_Oe1  
EEaf/D/jt  
2B# ]z  
//打印回应的头信息 ,4-)  e  
public void logResponseHead(HttpURLConnection con) )k.[Ve  
{ 'wd-!aZAd  
for(int i=1;;i++) SY` U]-h  
{ IQS:tL/  
String header=con.getHeaderFieldKey(i); T>&d/$;]  
if(header!=null) wnL\.%Y^  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _d'x6$Jg  
Utility.log(header+" : "+con.getHeaderField(header)); 24)3^1P\V  
else gUl Z cb  
break; >FO=ioNY  
} A,@"(3  
} r\?*?sL  
M_DkjuR  
54-x 14")  
public void splitterStop() Q&7Qht:ea:  
{ pw .(6"  
bStop = true; QaV*}W  
} ~V4|DN[I  
[aW#7  
-!" 8j"pA:  
} <KCgtO  
e5Z\v0  
=W?c1EPLCx  
/* ;#*mB`  
**FileAccess.java 7Uh}|6PU  
*//文件访问(定位,写) i "xq SLf=  
package NetFox; O`4X[r1LD  
import java.io.*; 6gn|WO=W f  
mvnK)R_  
l"64w>,  
public class FileAccessI implements Serializable{ +4 dHaj6  
e3.TGv7=  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .,4&/cd  
RandomAccessFile oSavedFile; xxYFWvi  
long nPos; ( s*}=  
QLn5:&  
K4~dEZ   
public FileAccessI() throws IOException Sq,x@  
{ .%o:kq@B  
this("",0); NGxuwHIQ8  
} 8LOzL,Ah  
x!J L9  
&,+ZN A`P  
public FileAccessI(String sName,long nPos) throws IOException )+J?(&6  
{ | e+m!G1G  
oSavedFile = new RandomAccessFile(sName,"rw"); 15B$Sp!/`e  
this.nPos = nPos; ZD*>i=S  
oSavedFile.seek(nPos); g`6S*&8I  
} Gl+}]Vn[n  
E yuc~[  
,QDq+93  
public synchronized int write(byte[] b,int nStart,int nLen) }-!$KR]:s  
{ m&2m' =(  
int n = -1; }w$/x<Q[  
try{ jhHb[je~{4  
oSavedFile.write(b,nStart,nLen); *GA#.$n  
n = nLen; `7NgQ*g.d/  
} Z`[j;=[  
catch(IOException e) 0xsvxH"*  
{ 3x#G SS  
e.printStackTrace (); >Kx l+F  
}  mJ-@:5  
oR~+s &c  
jRGG5w}  
return n; yy9Bd>  
} SL(Q;_  
u931^~Ci  
i''dY!2  
} 0]T ;{  
iS{)Tll}&  
1oC/W?l^  
/* 0-QkRr_ I  
**SiteInfoBean.java Z|)~2[Roa  
*/ b{sFN !  
package NetFox; wM><DrQ  
=w8*n2  
>k:)'*  
public class SiteInfoBean { ,5q^/h  
t ;[Me0  
t.m $|M>  
private String sSiteURL; //Site's URL ivt\| >  
private String sFilePath; //Saved File's Path !-: a`Vs+  
private String sFileName; //Saved File's Name 2)G ZU  
private int nSplitter; //Count of Splited Downloading File X;-,3dy  
a].Bn#AH!C  
]UMwpL&rY  
public SiteInfoBean() ;$Wa=wHb  
{//nSplitter的缺省值为5 #GTmC|[  
//default value of nSplitter is 5 r/PsFv{8  
this("","","",5); 3#dUQ1qo6  
} 'oo]oeJ-  
Cu >pql<O  
k (Ow.nkb  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -WEiY  
{ 7"M7N^  
sSiteURL= sURL; l_DPlY  
sFilePath = sPath; %e _WO,R  
sFileName = sName; U9Y'eP.2  
this.nSplitter = nSpiltter; u+{5c5_  
rGoB&% pc  
L/V3sSt  
} EQg 6*V  
o#;w >-  
1W5YS +pf  
public String getSSiteURL() cZ5[A  T  
{ 2t_E\W7w+  
return sSiteURL; MEg|AhP  
} 9~a_^m/  
y#r=^r]l)  
U; ev3  
public void setSSiteURL(String value) lnTl"9F  
{ aFKks .n3  
sSiteURL = value; Il!iqDHz3  
} hd+JKh!u  
F/mD05{  
8amtTM  
public String getSFilePath() 594$X@ !v  
{ \,~gA   
return sFilePath; 0\u_ \%[  
} WpRi+NC}ln  
CKj3-rcF(  
|`#[jHd  
public void setSFilePath(String value) Ie``W b=  
{ (Iu5QLE  
sFilePath = value; =$f xK  
} O>H4hp  
\}Hk`n)Aq  
b@nbXm]Z  
public String getSFileName() S&@~F|  
{ 6jom6/F 4  
return sFileName; B,}%1+*  
} {?,:M  
9'O<d/xj/  
J0^p\mG  
public void setSFileName(String value) AlGD .K  
{ ,v(G2`Z  
sFileName = value; GMd81@7  
} #~nI^ ggW  
vrh}X[JEw'  
<PXA`]x~  
public int getNSplitter() |qfnbi-\  
{ D`iWf3a.  
return nSplitter; L[<MBgF Kv  
} SrU,-mA W  
L[ rJ7:  
*j8w" 4  
public void setNSplitter(int nCount) &:w{[H$-  
{ :'#B U:  
nSplitter = nCount; hnL(~  
} % kKtPrT  
} jUdW o}/  
HH8a"Hq)  
_/7[=e}y  
/* tlG&PVvr  
**Utility.java ;v#~ o*  
*/ f H}`  
package NetFox; m&b!\"0  
 Ws}u4t  
8ec~"vGLz~  
public class Utility { 7J##IH+z35  
Oxy. V+R  
"!r7t4  
public Utility() BB=%tz`B  
{ cYW F)WAog  
;<MHDm D  
[BmondOx  
} `ffWV;P  
IB(5 &u.  
//线程睡眠 N(/DC)DJg  
public static void sleep(int nSecond) V<P@hAAr  
{ ZJ  u\  
try{ 8%I4jL<  
Thread.sleep(nSecond); 7S),:Uy[\  
} RVX-3FvP  
catch(Exception e) ;w[|IRa  
{ :@19,.L  
e.printStackTrace (); '0z@Jevd?  
} GXJJOy1"!  
} ln#Lx&r;|  
A.*}<  
//日志 TE^BfAw@  
public static void log(String sMsg) Uo5l =\  
{ cD]{ Nn  
System.err.println(sMsg); L@9"6&  
} bZ:w_z[3=  
ZN',=&;n'  
5H`k$[3V  
public static void log(int sMsg) ?ZE1>L7e  
{ 8BC}D+q  
System.err.println(sMsg); !Vv$  
} ^=FtF9v  
} ?,TON5Fl-  
 jats)!:  
9Jaek_A`  
/* Z3T:R"l;  
**TestMethod.java |Zncr9b  
*/ !$f@j6.  
package NetFox; )# M*@e$k  
Ga"$_DyM  
5}E8Tl  
public class TestMethod { kMf]~EZ?  
2Pasmh  
?RA^Y N*9  
public TestMethod() Azq,N@HO  
{ ///xx/weblogic60b2_win.exe ; Rt?&&W  
try{ Skq%S`1%Q  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d*7 Tjs{\  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b:Wl B[5  
SiteFileFetch fileFetch = new SiteFileFetch(bean); rW&8#&  
fileFetch.start(); bxK1v7  
} &=xm>;`3  
catch(Exception e){e.printStackTrace ();} cdf8YN0!  
=0MW+-  
/0\m;&  
} {{SeD:hx  
l%rwJLN1  
/t(dhz&xN  
public static void main(String[] args) X+ h|sy  
{ #=q)>+\  
new TestMethod(); "#qyX[\  
} Ks{^R`O au  
} B}C"Xc  
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