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
  • 11432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
/* }mq6]ZrK  
**SiteFileFetch.java `nv~NLkl  
*/ RD'Q :W  
package NetFox; #crQ1p) \  
import java.io.*; 5Y'qaIFR  
import java.net.*;  ~f1%8z  
lVR~Bh  
9_rYBX  
public class SiteFileFetch extends Thread { NAQAU *yP  
)Y6 +  
i6tf2oqO7  
SiteInfoBean siteInfoBean = null; //文件信息Bean o_Z5@F  
long[] nStartPos; //开始位置 K&ZtRRDd  
long[] nEndPos; //结束位置 .4M.y:F  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 so)[59M7  
long nFileLength; //文件长度 H*&f:mfq  
boolean bFirst = true; //是否第一次取文件 z/WE,R  
boolean bStop = false; //停止标志 [.'|_l  
File tmpFile; //文件下载的临时信息 <+Dn8  
DataOutputStream output; //输出到文件的输出流 3<Zq ]jk?n  
bv9i*]  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) gG:Vt}N  
public SiteFileFetch(SiteInfoBean bean) throws IOException EQyC1j  
{ LX7FaW  
siteInfoBean = bean; '4Ixqb+  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); 4Lh!8g=/  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); [.8BTj1%  
if(tmpFile.exists ()) %C'?@,7C  
{ YpZ+n*&+  
bFirst = false; fk[-mZ  
read_nPos(); H*QIB_  
} V b4#,  
else YEs&  
{ 7>|J8*/Nd  
nStartPos = new long[bean.getNSplitter()]; ,o{9$H5{  
nEndPos = new long[bean.getNSplitter()]; *:YiimOY"  
} "Hb"F?Yb  
KRLQ #,9  
WJndoB.f[2  
q J=~Y|(  
} D>@I+4{p  
be{H$9'  
3n1;G8Nf  
public void run() "XKy#[d2  
{ m )zUU  
//获得文件长度 ^ f &XQQY  
//分割文件 +EAsW(F1  
//实例FileSplitterFetch @ ZwvBH  
//启动FileSplitterFetch线程 =wHVsdNCN  
//等待子线程返回 Zq|I,l0+E  
try{ t#/YN.@r  
if(bFirst) !t %j?\f  
{ VT%NO'0  
nFileLength = getFileSize(); /W30~y  
if(nFileLength == -1) :P\7iW  
{ Ic:(Gi- %  
System.err.println("File Length is not known!"); ,I$`-$_'  
} el<s8:lA  
else if(nFileLength == -2) B5VKs,g  
{ ygS;$2m%2  
System.err.println("File is not access!"); y$F'(b| )  
} AGO+p(6d=g  
else Ae^~Cz1qz  
{ Co_A/  
for(int i=0;i<nStartPos.length;i++) tr3! d_  
{ ?|C2*?hZ+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); H8^(GUhyp  
} eRstD>r  
for(int i=0;i<nEndPos.length-1;i++) uk]$#TV*q>  
{ ua Gk6S  
nEndPos = nStartPos[i+1]; +I:Unp  
} };bEU wGWf  
nEndPos[nEndPos.length-1] = nFileLength; nQtWvT  
} uR4z &y  
} PbgP\JeX  
"f2$w  
}J`w4P  
//启动子线程 Nk 8B_{  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length];  O67W&nz  
for(int i=0;i<nStartPos.length;i++) mPK:R^RjG&  
{ o>i4CCU+  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B6As,)RjD:  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4*#18<u5  
nStartPos,nEndPos,i); qI9z;_,gNz  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K5VWt)Z#  
fileSplitterFetch.start(); m6K}|j  
} 6NuD4Ga  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S_4?K)n #  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,~$p,ALwN7  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~ 'H ]jN  
nEndPos = " + nFileLength); n;C :0  
// fileSplitterFetch[nPos.length-1].start(); _|\~q[ep  
GPv1fearl  
82qoGSD.  
//等待子线程结束 EHIF>@TZ  
//int count = 0; wn, KY$/  
//是否结束while循环 qzLPw*;  
boolean breakWhile = false; ~i{(<.he  
f4b/NG|  
)Y0!~# `  
while(!bStop) .x.]`b(  
{ ")5":V~fN  
write_nPos(); syj0.JD  
Utility.sleep(500); l -mfFN  
breakWhile = true; {n.PF8A5X  
El".I?E*  
7\[@ m3s  
for(int i=0;i<nStartPos.length;i++) M}-Rzc  
{ |?xN\O^#}  
if(!fileSplitterFetch.bDownOver) aQcleTb  
{ $am$ EU?s  
breakWhile = false; Xp% v.M  
break; wqs? 828x  
} Hqx-~hQO  
} mzKiO_g}  
if(breakWhile) hJ? O],4J  
break; 9(7-{,c  
_p/UsJ  
aEWWP]  
//count++; ^j7Vt2-  
//if(count>4) t+ G#{n  
// siteStop(); A#<?4&  
} V>LwqS~`  
.},'~NM]  
yNo0ubY  
System.err.println("文件下载结束!"); *W1dG#Np}  
} ~?Pw& K2  
catch(Exception e){e.printStackTrace ();} 2tEkj=fA-  
} [Ek7b *  
M `M5'f  
ZzpUUH/r  
//获得文件长度 LEf^cM=>  
public long getFileSize()  vF+7V*<  
{ n\D&!y[]F  
int nFileLength = -1; vX"*4m>b?+  
try{ ~<5!?6Yt  
URL url = new URL(siteInfoBean.getSSiteURL()); "| g>'wM*  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @%uUiP0  
httpConnection.setRequestProperty("User-Agent","NetFox"); @ioJ] $o7  
E_wCN&`[  
[ /b2=>  
int responseCode=httpConnection.getResponseCode(); j0aXyLNX  
if(responseCode>=400) y9GoPC`z  
{ ]^7@}Ce_  
processErrorCode(responseCode); ^|(LAjet  
return -2; //-2 represent access is error 5d^sA;c  
} 5m 4P\y^a  
=R|HV;9 h  
]|a g  
String sHeader;  A,<E\  
>Q;l(fdj  
[yQt^!;  
for(int i=1;;i++) _8J.fT$${  
{ p38-l'{#  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); JR21>;l#2  
//Utility.log(in.readLine()); HM1Fz\Sf  
sHeader=httpConnection.getHeaderFieldKey(i); p%Vt#?q  
if(sHeader!=null) &`r-.&Y  
{ -3 *]G^y2  
if(sHeader.equals("Content-Length")) 0i>5<ej,f  
{ k%#EEMh  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "Gzz4D  
break; lgy <?LI\  
} @Uvz8*b6  
} tSUEZ62EY  
else 5Ln,{vsv  
break; G~[x 3L'  
} 1n8/r}q'H  
} &wawr2)}  
catch(IOException e){e.printStackTrace ();} Q"d^_z ]K  
catch(Exception e){e.printStackTrace ();} &PHTpkaam  
Bm<`n;m  
ltSU fI  
Utility.log(nFileLength); ,w4(kcg%iQ  
: *#-%0  
o5PO =AN  
return nFileLength; rXP,\ ]r+  
} AV]2 euyn  
my1@41 H  
J yK3{wYS  
//保存下载信息(文件指针位置) 3;9^  
private void write_nPos() WE#^a6  
{ V2EUW!gn 2  
try{ f'RX6$}\1X  
output = new DataOutputStream(new FileOutputStream(tmpFile)); R) h#Vc(  
output.writeInt(nStartPos.length); %aCqi(.7  
for(int i=0;i<nStartPos.length;i++) Ic<2QknmP  
{ Wvh#:Z  
// output.writeLong(nPos); ebhXak[w  
output.writeLong(fileSplitterFetch.nStartPos); u&vf+6=9Dd  
output.writeLong(fileSplitterFetch.nEndPos); khxnlry  
} +\]\[6  
output.close(); jB2[(  
} v{4$D~I  
catch(IOException e){e.printStackTrace ();}  K5h  
catch(Exception e){e.printStackTrace ();} t =iIY`Md%  
} <xm7qmqI  
%wy.TN  
>]TWXmx/w  
//读取保存的下载信息(文件指针位置) 9.-S(ZO  
private void read_nPos() C{rcs'  
{ ~ .g@hS8>  
try{ M7~2iU<#  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 6d}lw6L  
int nCount = input.readInt(); (ZZ8L-s  
nStartPos = new long[nCount]; ]_gU#,8  
nEndPos = new long[nCount]; q3!bky\  
for(int i=0;i<nStartPos.length;i++) lUZ+YD4  
{ .`eN8Dl1  
nStartPos = input.readLong(); h[Y1?ln&h  
nEndPos = input.readLong(); K\r8g=U  
} + &Eqk  
input.close(); YD6'#(  
} (w3YvG.  
catch(IOException e){e.printStackTrace ();} _V6ukd"B~  
catch(Exception e){e.printStackTrace ();} ouQ T  
} M%m4i9~!?  
d7upz]K9g  
[z{1*Xc  
private void processErrorCode(int nErrorCode) g! |kp?  
{ =dKtV.L  
System.err.println("Error Code : " + nErrorCode); _B<X`L =  
} rb.N~  
$U WZDD  
6bC3O4Rw  
//停止文件下载 _`T_">9r  
public void siteStop() ?fSG'\h>  
{ S,UDezxg  
bStop = true; b4kgFA  
for(int i=0;i<nStartPos.length;i++) Jnov<+  
fileSplitterFetch.splitterStop(); T8$y[W-c  
V 5mTP'  
g) jYFfGfH  
} ~$^XP.a.  
} )ez9"# MH'  
//负责部分文件的抓取 99QU3c<.  
**FileSplitterFetch.java 3=j"=-=  
*/ PJH&  
package NetFox; rV#ch(  
/U9"wvg  
:$c |  
import java.io.*; ;.980+i1  
import java.net.*; ;e*!S}C,  
%h!B^{0  
sO@Tf\d  
public class FileSplitterFetch extends Thread { zrb}_  
Q![@c   
8d'0N  
String sURL; //File URL (jE9XxQY  
long nStartPos; //File Snippet Start Position 6i/(5 nQ  
long nEndPos; //File Snippet End Position 26h21Z16q  
int nThreadID; //Thread's ID b ]KBgZ  
boolean bDownOver = false; //Downing is over R\[e!g*I  
boolean bStop = false; //Stop identical XSLFPTDEc  
FileAccessI fileAccessI = null; //File Access interface ;i+jJ4  
 b>ySv  
$!t4r  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Km$\:Xo  
{ _t^&Ah*  
this.sURL = sURL; Dlvz )  
this.nStartPos = nStart; NzvXN1_%  
this.nEndPos = nEnd; k<?b(&`J  
nThreadID = id; dy[X3jQB  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 (sZ"iGn%  
} 6'f;-2  
ckCE1e>s  
mC#>33{  
public void run() 0g8NHkM:2a  
{ K-Ef%a2#`  
while(nStartPos < nEndPos && !bStop) gB33?  
{ ;$g?T~v7  
V'gh 6`v  
R:qW;n%AF  
try{ f!X[c?Xy"  
URL url = new URL(sURL); !4+<<(B=E  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1 'Dai`  
httpConnection.setRequestProperty("User-Agent","NetFox"); p!%pP}I  
String sProperty = "bytes="+nStartPos+"-"; OjA,]Gv6  
httpConnection.setRequestProperty("RANGE",sProperty); CqC`8fD1  
Utility.log(sProperty); 9\(| D#  
C3g_! dUs  
VIf.q)_k  
InputStream input = httpConnection.getInputStream(); ;O,jUiQ  
//logResponseHead(httpConnection); qHsA1<wg  
N;%6:I./  
f$QNg0v  
byte[] b = new byte[1024]; v3>UV8c'  
int nRead; m1AJ{cs  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) om>KU$g  
{ 8&dF  
nStartPos += fileAccessI.write(b,0,nRead); <#4h}_xA%  
//if(nThreadID == 1) HZZn'u  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w0unS`\4  
} r3?o9D>  
YS_; OFsd  
\i &<s;  
Utility.log("Thread " + nThreadID + " is over!"); *LY8D<:zs  
bDownOver = true; U6s[`H3I{  
//nPos = fileAccessI.write (b,0,nRead); f|(M.U-  
} `Pnoxm'  
catch(Exception e){e.printStackTrace ();} ~g t@P  
} dj%!I:Q>u  
} W2!+z{:m  
#g!.T g'  
2 yz _  
//打印回应的头信息 _q^E,P  
public void logResponseHead(HttpURLConnection con) 5!9zI+S|=`  
{ Flb&B1  
for(int i=1;;i++) xgtR6E^k  
{ yB6?`3A:  
String header=con.getHeaderFieldKey(i); -UT}/:a  
if(header!=null) HxI" 8A  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); c:.eGH_f  
Utility.log(header+" : "+con.getHeaderField(header)); &%Tj/Qx  
else ySI !d|_  
break; g9F?z2^  
} #`s"WnP9'!  
} \l3h0R  
m#p'iU*va,  
N{>n$ v}  
public void splitterStop() > Nr#O  
{ #X"@<l4F  
bStop = true; kG*~ |ma  
} fF kj+  
|wj?ed$ f  
8dhUBJ0_  
} FN73+-:n:j  
i}?>g-(  
QmIBaMI#  
/* 1BEHw?dLU  
**FileAccess.java U/BR*Zn]*  
*//文件访问(定位,写) Tm?#M&'  
package NetFox; { (}By/_  
import java.io.*; Y <qm{e  
9_s`{(0?  
rrv%~giU  
public class FileAccessI implements Serializable{ [ikOb8 G#  
<of^AKbt  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 KK &?gTa  
RandomAccessFile oSavedFile; {VoHh_[5%  
long nPos; bN@ l?w  
cN9t{.m  
u<&m]] *  
public FileAccessI() throws IOException H>@+om  
{ t |oR7qa{w  
this("",0); CJI~_3+K  
} ;A!BVq  
7x a>  
Q NVa?'0"Y  
public FileAccessI(String sName,long nPos) throws IOException  8dyg1F  
{ wlmRe`R  
oSavedFile = new RandomAccessFile(sName,"rw"); {]|J5Dgfe  
this.nPos = nPos; 0SPk|kr  
oSavedFile.seek(nPos); dcT80sOC  
} */DO ex"y  
{1 94!S4z  
0qT%!ku&  
public synchronized int write(byte[] b,int nStart,int nLen) c[Zje7 @  
{ E1f\%!2l  
int n = -1; 7"xd1l?zz  
try{ 6S\8$  
oSavedFile.write(b,nStart,nLen); {FTqu.  
n = nLen; @xZR9Z8]L  
} RCLeA=/N@0  
catch(IOException e) 4v|W-h"K  
{ u> / TE  
e.printStackTrace (); 61 ~upQaR  
} g$o&Udgs  
;6hOx(>`=  
2)~> R  
return n; 1@=po)Hnp  
} '[O;zJN;  
uRe'%?W  
da~],MN  
} tFl"n;~T  
&YeA:i?  
P L+sR3bR  
/* 1g~R/*Jo  
**SiteInfoBean.java j 1HW._G  
*/ /|#fejPh  
package NetFox; W|(1Y D  
kz7(Z'pw  
Fea(zJ_  
public class SiteInfoBean { /JU.?M35  
]jRfH(i  
?b5 ^  
private String sSiteURL; //Site's URL !$>R j  
private String sFilePath; //Saved File's Path Nl(Foya%)  
private String sFileName; //Saved File's Name VOh4#%Vj  
private int nSplitter; //Count of Splited Downloading File EAby?51+  
F1Bq$*'N$w  
y L~W.H  
public SiteInfoBean() -1@<=jX3_  
{//nSplitter的缺省值为5 $ o#V#  
//default value of nSplitter is 5 b\+`e b8_  
this("","","",5); [;sRV<  
} Mh 7DV  
{T~#?v(  
-RK- Fu<e  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -`TEVS?`l  
{ 9k[9P;"F:  
sSiteURL= sURL; XHGFf_kW_N  
sFilePath = sPath; LB?u8>a' I  
sFileName = sName; %GIr&V4|  
this.nSplitter = nSpiltter; `x%>8/  
"Os_vlapHo  
xFg>SJ7]  
} u,Kly<0j  
S?BG_J6A7  
26x[X.C:  
public String getSSiteURL() 1 I",L&S1  
{ Ef13Q]9|  
return sSiteURL; &UlWCOo8  
} CQDkFQq-dq  
1hNq8*|  
*bpD`s @  
public void setSSiteURL(String value) @2v_pJy^  
{ =rX>1  
sSiteURL = value; IRqy%@)  
} 9490o:s  
X+]G-  
3%=~) 7cF  
public String getSFilePath() zT?D<XW>1  
{ DrK{}uM  
return sFilePath; y Fq&8 x<X  
} =[jXe  
hqkz^!rp  
URbletSBQ  
public void setSFilePath(String value) ?p8_AL'RS  
{ >t_6B~x9  
sFilePath = value; ?= fyc1  
} F`]2O:[  
WQO) =n  
G9<X_  
public String getSFileName() /fV;^=:8c  
{ q?/a~a  
return sFileName; T:W4$P  
} )p%E%6p  
w$-6-rE]d  
kX2rp?{  
public void setSFileName(String value) BsYa3d=}  
{ YLn?.sV{[0  
sFileName = value; Z0r?| G0  
} O463I.XAP  
-v|qZ'  
zjoq6  
public int getNSplitter() e6RPIg  
{ TBU&6M>{3  
return nSplitter; q{;:SgZ  
} Nf1-!u7  
k7usMVAA  
a-L;*  
public void setNSplitter(int nCount) *,WU?tl&  
{ fIv*T[  
nSplitter = nCount; -4_$ln w$  
} x5*!Wx   
} (qulwOt~w  
sY f~c0${  
G {%LB}2  
/* fNZ__gO!%  
**Utility.java t |A-9^t'!  
*/ (0y~%J  
package NetFox; WlBc.kFck  
R`^_(yn>  
hSyql  
public class Utility { #],&>n7'  
{o`] I>gb  
i5,kd~%O  
public Utility() y>e.~5;  
{ _[ZO p ~  
< F+l  
C/6V9;U  
} :'*~uJrR  
3y8G?LL/[7  
//线程睡眠 9\JF`ff_  
public static void sleep(int nSecond) r#] WI|  
{ $,Yd>%Y  
try{ `XEr(e9  
Thread.sleep(nSecond); 6MdiY1Lr!K  
} ><HE;cVg?  
catch(Exception e) l}sjD[2  
{ W'+:'_{j:  
e.printStackTrace (); n3 r3"~i  
} j Dv{/ )  
} G?/DrnK:  
_D(rI#q  
//日志 2u*KM`fa`  
public static void log(String sMsg) LvUj9eVb/L  
{ rFYWs6  
System.err.println(sMsg); _&ks1cw  
} A`o8'+`C  
PGV/ h  
qE3UO<FA  
public static void log(int sMsg) %m$Sp47  
{ ?|B&M\}g  
System.err.println(sMsg); a8Nh=^Py  
} mmRJ9OhS  
} =k`Cr0aPF  
h6`6tk  
UVIKQpA]A  
/* uT7B#b7  
**TestMethod.java 1 \6D '/G  
*/ KE3;V2Ym f  
package NetFox; eHNyNVz  
\%N!5>cZ{  
Oh6fj}eK  
public class TestMethod { ! lc[  
+<3X J7D  
j@uOOhy  
public TestMethod() e@* EzvO  
{ ///xx/weblogic60b2_win.exe ?\s+EE&-  
try{ /9p wZ%:<  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); !fR3 (=oN  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dNL(G%Qj+"  
SiteFileFetch fileFetch = new SiteFileFetch(bean); M>ruKHipFE  
fileFetch.start(); @8rx`9  
} x!58cS*  
catch(Exception e){e.printStackTrace ();} Y+u_IJ  
} .y 1;.  
.I0qGg  
} Bj-: #P@  
_k ~KZ;l  
l &5QZI0I  
public static void main(String[] args) 1--C~IjJ+  
{ Ay w ;N  
new TestMethod(); fbKkq.w  
} KP5C} ZK+s  
} ?8Z0Gqt74  
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
批量上传需要先选择文件,再选择上传
认证码:
验证问题:
10+5=?,请输入中文答案:十五