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
  • 11109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
/* l+[:Cni  
**SiteFileFetch.java 8[;vC$  
*/ *,mI=1  
package NetFox; T'9ZR,{F  
import java.io.*; -Arsmo  
import java.net.*; XeX"IhgS>E  
jUEgu  
ki?h7  
public class SiteFileFetch extends Thread { ! !A0K"h  
#F`A(n  
Dn6U8s&  
SiteInfoBean siteInfoBean = null; //文件信息Bean h Ta(^  
long[] nStartPos; //开始位置 o:D,,MkSw  
long[] nEndPos; //结束位置 %Yj%0  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 J91[w?,  
long nFileLength; //文件长度 ,Cb3R|L8  
boolean bFirst = true; //是否第一次取文件 12a`,~  
boolean bStop = false; //停止标志 yL*]_  
File tmpFile; //文件下载的临时信息 s'h;a5Q1'Q  
DataOutputStream output; //输出到文件的输出流 =hkYQq`Q  
'`3#FCg  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) @@)2 12  
public SiteFileFetch(SiteInfoBean bean) throws IOException 1>"-!ADm  
{ !bP%\)5  
siteInfoBean = bean; "!~o  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); &E_a0*)e  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); 0^lWy+  
if(tmpFile.exists ()) CmZayV  
{ v8)"skVnFG  
bFirst = false; CuWJai:nQ;  
read_nPos(); |@vkQ  
} CZ<T@k  
else vd{QFJ  
{ P( hGkY=(  
nStartPos = new long[bean.getNSplitter()]; ")T\_ME  
nEndPos = new long[bean.getNSplitter()]; LWyr  
} g w" \pD  
N-gYamlQ  
u.|Z3=?VG  
F!]Sr'UA  
} Ot2o=^Ng  
} o%^ Mu B  
L5-|-PP|;  
public void run() MKl0 d  
{ _!nsEG VV  
//获得文件长度 q`VL i  
//分割文件 WwDM^}e  
//实例FileSplitterFetch 3 r&  
//启动FileSplitterFetch线程 O$<>v\NC?  
//等待子线程返回 :OG I|[  
try{ iQ;p59wSzL  
if(bFirst) KwuucY  
{ Upe}9xf  
nFileLength = getFileSize(); ]mTBD<3\  
if(nFileLength == -1) 1^!SuAA@  
{ >Icr4?zq  
System.err.println("File Length is not known!"); `#N/]4(j  
} |_V(^b}  
else if(nFileLength == -2) `POzwYh  
{ wI$ a1H  
System.err.println("File is not access!"); {FNkPX  
} ?, S/>SP  
else DN*5q9.  
{ l3>S{  
for(int i=0;i<nStartPos.length;i++) \84t\jKR  
{ 9;E=w+  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); yD7BZI xW  
} ;-+q*@sa]  
for(int i=0;i<nEndPos.length-1;i++) or/gx3  
{ zx3gz7>k;  
nEndPos = nStartPos[i+1]; ^7-zwl(>?N  
} CL|/I:%0  
nEndPos[nEndPos.length-1] = nFileLength; c$O8Rhx  
} ,o& C"sb  
} S#7YJ7 K"N  
MUO<o  
\$ytmtf5  
//启动子线程 <$A,Ex94  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; c0qp-=^&.  
for(int i=0;i<nStartPos.length;i++) fpD$%.y'J  
{ 5 4gr'qvr  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Zw.8B0W  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7>FXsUt_  
nStartPos,nEndPos,i);  =<HDek  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ld4U  
fileSplitterFetch.start(); UB/> Ro  
} ZJYn[\]  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qp>leEs]+6  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CU'JvVe3  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", l~c[}wv  
nEndPos = " + nFileLength); Zxa.x?:?n  
// fileSplitterFetch[nPos.length-1].start(); t`Kbm''d[  
6b2UPI7m~  
szI7 I$Qb  
//等待子线程结束 M/zO|-j&  
//int count = 0; ,_2-Op  
//是否结束while循环 T5S4,.o9W  
boolean breakWhile = false; Yj %]|E-  
a.Ho>(V/4  
3JCo!n0   
while(!bStop) ]&cnc8tC  
{ :xd;=;q5  
write_nPos(); . %RM8  
Utility.sleep(500); b)LT[>f  
breakWhile = true; L:z0cvn"  
ag-A}k>v  
X8 nos  
for(int i=0;i<nStartPos.length;i++) o NtFYY  
{  : T*Q2  
if(!fileSplitterFetch.bDownOver) BOs/:ZbK0W  
{ LG #^g6P  
breakWhile = false; / ^.|m3  
break; KZm&sk=QM-  
} _yg_?GH  
} ^L[:DB{Z  
if(breakWhile) 2jsbg{QS#_  
break; *FlPGBjJ  
"6B7EH  
$v^hzC  
//count++; -@orIwA&  
//if(count>4) %TB(E<p`  
// siteStop(); S c)^k  
} _?{7%(C  
JJ?{V:  
Ei;tfB  
System.err.println("文件下载结束!"); ([>ecS@eO  
} z _!ut  
catch(Exception e){e.printStackTrace ();} ARk(\,h  
} %opBJ   
xoaO=7\io  
+$2{u_m,  
//获得文件长度 S;|:ci<[=  
public long getFileSize() /jbAf]"F;  
{ ?t#wK}d.  
int nFileLength = -1; ?#xl3Z ;I  
try{ sX>u.  
URL url = new URL(siteInfoBean.getSSiteURL()); 9d(\/ 7  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); h^M_yz-f  
httpConnection.setRequestProperty("User-Agent","NetFox");  bGRt  
qQ@| Cj  
WK ~H]w  
int responseCode=httpConnection.getResponseCode(); hW^,' m  
if(responseCode>=400) x 7j#@C  
{ %)ho<z:7U  
processErrorCode(responseCode); K,b M9>}  
return -2; //-2 represent access is error 3DU1c?M:  
} Ndmt$(b  
Fn4v/)*H  
04a ^jjc  
String sHeader; aSL`yuXu  
1+l8%G=hB  
u-_r2U  
for(int i=1;;i++) Hbm 4oYN  
{ _;lw,;ftA  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tFN >]`Z  
//Utility.log(in.readLine()); dzVi ~wt_&  
sHeader=httpConnection.getHeaderFieldKey(i); U|^xr~q!f-  
if(sHeader!=null) $=aO*i  
{ @6u/)>rI  
if(sHeader.equals("Content-Length")) 7|rH9Bc{U  
{ tne_]+  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %,>z`D,Hg  
break; h ><Sp*z_V  
} E$8JrL  
} mx c)Wm<4  
else Q7%4`_$!  
break; b 2gng}  
} h Yu6PWK  
} Z;0~f<e%  
catch(IOException e){e.printStackTrace ();} X{9^$/XsJ  
catch(Exception e){e.printStackTrace ();} q z)2a2C  
a#oROb-*~  
 Fr%#  
Utility.log(nFileLength); ! 'zd(kv<  
T$Z9F^w  
TpjiKM  
return nFileLength; m]p{]6h  
} Q*ITs!~Z  
\pmS*Dt  
wxN)d B  
//保存下载信息(文件指针位置) (In{GA7 ;  
private void write_nPos() f/Gx}x=  
{ 53Adic  
try{ &L o TO+  
output = new DataOutputStream(new FileOutputStream(tmpFile)); o%d TcoCN  
output.writeInt(nStartPos.length); @s5=6z]=H  
for(int i=0;i<nStartPos.length;i++) eP{srP3 9  
{ J-W9Bamx  
// output.writeLong(nPos); ^-o{3Q(w  
output.writeLong(fileSplitterFetch.nStartPos); /:dLqyQ_V  
output.writeLong(fileSplitterFetch.nEndPos); }nmlN  
} 2YD\KXDo  
output.close(); i FI74COam  
} n1[c\1   
catch(IOException e){e.printStackTrace ();} t],a1I.gk  
catch(Exception e){e.printStackTrace ();} <_?zln:4.  
} j,IRUx13f  
!MbzFs~  
[%W'd9`>  
//读取保存的下载信息(文件指针位置) 86&M Zdv6  
private void read_nPos() KK|w30\f  
{ 1wSAwpz  
try{ NvK9L.K  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); EF/d7  
int nCount = input.readInt(); {X{R]  
nStartPos = new long[nCount]; C.j+Zb1Z(  
nEndPos = new long[nCount]; KE?t?p  
for(int i=0;i<nStartPos.length;i++) ,'L>:pF3  
{ PyeNu3Il4  
nStartPos = input.readLong(); 6opin  
nEndPos = input.readLong(); *TOdIq&z  
} .i0K-B  
input.close(); kpOdyn(  
} 5LeZ ?'"c  
catch(IOException e){e.printStackTrace ();} *k?:k78L  
catch(Exception e){e.printStackTrace ();} E)b$;'  
} _&KqmQ8$7  
awLvLkQb{  
H MOIUd  
private void processErrorCode(int nErrorCode) P^Hgm  
{ ~ |G&cg  
System.err.println("Error Code : " + nErrorCode); lg%fjBY  
} Vaxg   
!-I,Dh-A  
DE13x *2  
//停止文件下载 I8#2+$Be+@  
public void siteStop() e =amh  
{ ns[/M~_r  
bStop = true; 5eAZfe%H  
for(int i=0;i<nStartPos.length;i++) UmKE]1Yw4r  
fileSplitterFetch.splitterStop(); I}$`gUXX8x  
'|yxB')  
(P>nA3:UXB  
} *,u3Wm|7  
} 2=cx`"a$  
//负责部分文件的抓取 +LHU}'|  
**FileSplitterFetch.java c r=Q39{  
*/ 1(' wg!  
package NetFox; %-hSa~20  
uWS]l[Ga  
)Q2Ap&  
import java.io.*; t~2oEwTm  
import java.net.*; f\&X$g  
?G{0{ c2  
>t+ ENYb  
public class FileSplitterFetch extends Thread { &61U1"&$R  
lZzW- %K  
)@]%:m!ER  
String sURL; //File URL 7w )?s@CD  
long nStartPos; //File Snippet Start Position d<c29Y  
long nEndPos; //File Snippet End Position Omd;  
int nThreadID; //Thread's ID ss^a=?~  
boolean bDownOver = false; //Downing is over RhYe=Qh4{p  
boolean bStop = false; //Stop identical k@xinK%O{  
FileAccessI fileAccessI = null; //File Access interface EKc<|e,F  
.jRI $vm  
aIgexi,  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =%_=!%  
{ b42%^E  
this.sURL = sURL; ;@+ |]I  
this.nStartPos = nStart; FgdnX2s J  
this.nEndPos = nEnd; cXXZ'y>FP  
nThreadID = id; -"-.Z&#  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,fjY|ip  
} Qt u;_  
rrIyZ@_d9  
A}fm).Wp@  
public void run() hs6pp/h>  
{ M+"6VtZH  
while(nStartPos < nEndPos && !bStop) #p+iwW-  
{ HDm]njF%qQ  
2gWR2 H@  
wd:Yy  
try{  9q X$  
URL url = new URL(sURL); Y S3~sA  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); WZa6*pF  
httpConnection.setRequestProperty("User-Agent","NetFox"); -TD\?Q  
String sProperty = "bytes="+nStartPos+"-"; }L0 [ Jo:  
httpConnection.setRequestProperty("RANGE",sProperty); (bm^R-SbB  
Utility.log(sProperty); MqJTRBs%  
Zo UeLU  
B*/!s7c.  
InputStream input = httpConnection.getInputStream(); DG&'x;K"$  
//logResponseHead(httpConnection); 8Qi)E 1n  
 }$oS /bo  
c[ 2t,+O  
byte[] b = new byte[1024]; 3ynkf77cn  
int nRead; |bk9< i ?  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~[=<O s  
{ S1|5+PPs  
nStartPos += fileAccessI.write(b,0,nRead); `%YMUBaI  
//if(nThreadID == 1) |s3;`Nxu7  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m|NZ093d  
} u|KjoO   
Na@bXcz)  
Z?P^Y%ls  
Utility.log("Thread " + nThreadID + " is over!"); jCY~Wc  
bDownOver = true; 9]Jv >_W*  
//nPos = fileAccessI.write (b,0,nRead); tE %g)hL-  
} AojL4H|  
catch(Exception e){e.printStackTrace ();} y\v#qFVOZ  
} ~\=D@G,9  
} 7U7!'xU  
;R= n<=Axa  
re*Zs}(N\  
//打印回应的头信息 'VV U-)(8  
public void logResponseHead(HttpURLConnection con) 6B]=\H  
{ |!FQQ(1b  
for(int i=1;;i++) ?I]AE&4'  
{ DE.].FD'  
String header=con.getHeaderFieldKey(i); R;HE{q[ f  
if(header!=null) v4e4,Nt  
//responseHeaders.put(header,httpConnection.getHeaderField(header));  Z 9:  
Utility.log(header+" : "+con.getHeaderField(header)); AL":j6!OQ  
else 20I`F>-*  
break; 2]kGDeSr  
} k"#gSCW$  
} 4?Y7. :x  
ILr=< j  
1;[KBYUH  
public void splitterStop() +cfcr*  
{ 8SpG/gl"  
bStop = true; { <Gyjq  
} pZ8J\4+  
G:*vV#K  
OROvy  
} $e1.y b%  
9(t(sP_  
pPa]@ z~O  
/* .B~}hjOZK  
**FileAccess.java B*_K}5UO  
*//文件访问(定位,写) gaN/ kp  
package NetFox; uD/@d'd_4L  
import java.io.*; z5gVP8*z5  
UvGxA[~2+  
WVD48}HF-  
public class FileAccessI implements Serializable{ yKhI&  
z~2{`pET  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 W=HvMD  
RandomAccessFile oSavedFile; XaCvBQ  
long nPos; r10VFaly  
5Pf=Uj6D  
o2dO\$'  
public FileAccessI() throws IOException 7;+G)44  
{ Hc\C0V<  
this("",0); UYxn? W.g  
} a/ uo)']B  
%Bw:6Y4LZ  
xc*a(v0  
public FileAccessI(String sName,long nPos) throws IOException q\@_L.tc[  
{ (zFqb,P  
oSavedFile = new RandomAccessFile(sName,"rw"); Mf14> `<`  
this.nPos = nPos; wU|@fm"  
oSavedFile.seek(nPos); #czTX%+9(e  
} A|LO!P,w  
3E wdu  
6 D Xja_lp  
public synchronized int write(byte[] b,int nStart,int nLen) S'5)K  
{ /e"iY F  
int n = -1; WzstO}?P(  
try{ inh:b .,B  
oSavedFile.write(b,nStart,nLen); XB7*S*"!  
n = nLen; 46]BRL2 G  
} Iuz_u2"C  
catch(IOException e) ~*bfS}F8I  
{ /[dMw *SRz  
e.printStackTrace (); p _[,P7  
} FzEs1hpl  
9287&+,0r  
{@CQ (  
return n; -+{[.U<1jk  
} l<XYDb~op  
ntLEk fK{  
8\68NG6o  
} H?O5 "4a  
6!>p<p"Ns  
XfE0P(sE  
/* %SB4_ r*<  
**SiteInfoBean.java PwW$=M{\.  
*/ Xk.OyQ@  
package NetFox; K ,NmDc^  
8Azh&c  
,r*Kxy  
public class SiteInfoBean { EF!J#N2  
1N(#4mE=  
L9O;K$[s  
private String sSiteURL; //Site's URL N `:MF 9  
private String sFilePath; //Saved File's Path Yw#fQFm  
private String sFileName; //Saved File's Name _%R^8FjH*  
private int nSplitter; //Count of Splited Downloading File +r'&6Me!  
kf>3T@  
8OZasf  
public SiteInfoBean() =q0V%h{  
{//nSplitter的缺省值为5 ( 0/M?YQF  
//default value of nSplitter is 5 i=\)[;U  
this("","","",5); QTBc_Z  
} VOD-< "|  
Soq#cl'll-  
<qfAW?tF  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %W9R08`  
{ ~<!j]@.  
sSiteURL= sURL; %JrZMs>  
sFilePath = sPath; w^Y/J4 I0  
sFileName = sName; R/x3+_.f  
this.nSplitter = nSpiltter; ZeuL*c \  
AE>W$x8P  
Bk\Y v0  
} Wz.iDRFl  
w\s`8S  
:se$<d%  
public String getSSiteURL() 0F-{YQr>  
{ =s":Mx,o  
return sSiteURL; rlR!Tc>  
} (9RfsV4^  
7:olStK  
,93Uji[l  
public void setSSiteURL(String value) LUD .  
{ Fn .J tIu  
sSiteURL = value; ;+XrCy!.)L  
} J@:Q(  
B?i#m^S  
'y; Kj  
public String getSFilePath() s>o#Ob@4'  
{ )KE  
return sFilePath; &*>.u8:r  
} :.ZWYze  
h"+7cc@  
*Z"`g %,;  
public void setSFilePath(String value) &PE%tm  
{ Lq5xp<  
sFilePath = value; 60^j<O  
} -B#1+rUW  
WGn=3(4  
'Z~ZSu  
public String getSFileName() pZ'q_Oux  
{ enJ; #aA  
return sFileName; Qwpni^D8j  
} uQ-GJI^t  
(*$F7oO<  
2pdeJ  
public void setSFileName(String value) FShjUl>mV  
{ I;NW!"pU  
sFileName = value; Ur#jJR@%3  
} +Mq\3  
P4Pc;8T@!  
N\*oL*[j  
public int getNSplitter() <b H *f w  
{ nC p/.]Y*  
return nSplitter; k!x|oC0  
} =KHb0d |.  
@CzFzVmF"  
]S4"JcM  
public void setNSplitter(int nCount) 0\XWdTj{  
{ xg/(  
nSplitter = nCount; 7*uN[g#p  
} %urvX$r4K  
} ^}Vc||S  
neM.M)0  
c`;oV-f  
/* ~'lT8 n_  
**Utility.java IOZw[9](+  
*/ aI&~aezmN  
package NetFox; `hO%(9V9  
56z>/`=  
?@4Mt2Z\  
public class Utility { AB/${RGf+  
|K1S(m<F  
a6n@   
public Utility() 0RA#Y(IR  
{ xR0*w7YE  
_">F]ptI;  
tV(iC~/  
} 76rv$z{g^  
yS~Y"#F!.  
//线程睡眠 @/kI;8  
public static void sleep(int nSecond) ]:Ep1DIMl  
{ K9EHT-  
try{ e2 c'Wab  
Thread.sleep(nSecond); MS;^:t1`  
} d]e36Dwk  
catch(Exception e) <8 <P,  
{ V.:,Q  
e.printStackTrace (); )!27=R/  
} 2*V%S/cck  
} dPu27 "  
bs|gQZG  
//日志 E7/UsUV.  
public static void log(String sMsg) 8*u'D@0  
{ ;GM`=M4  
System.err.println(sMsg); )1Bz0:  
} C`[2B0  
C{/U;Ie-b  
#).^k-  
public static void log(int sMsg) o4p5`jOG@  
{ hx0t!k(3  
System.err.println(sMsg); zgjgEhnvU  
} Wd7*7']  
} Z0Sqw  
6<W^T9}v@/  
$V 3If  
/* \@Cz 32wg  
**TestMethod.java Q.$8>)  
*/ {2q"9Ox"  
package NetFox; (9]1p;  
9e`};DE   
VQ('ejv}/  
public class TestMethod { xMk>r1Ud  
RjVU m+<  
(.N n|lY<i  
public TestMethod() `/ T.u&QF  
{ ///xx/weblogic60b2_win.exe ~s&r.6 DW  
try{ v+x<X5u  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MMrN#&r  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); EgG3XhfS  
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4Mg%}/cC  
fileFetch.start(); vGsAM* vw6  
} -sv%A7i  
catch(Exception e){e.printStackTrace ();} *^@b0f~vj  
 cRK Lyb  
G!VEV3zT  
} ^/?7hbr  
]+,L/P  
[H\0 '  
public static void main(String[] args) 3. dSS  
{ O+mEE>:w%  
new TestMethod(); ^(  
} 92Gfxld\  
} x$jLB&+ICz  
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:
3+5=?,请输入中文答案:八 正确答案:八