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
  • 9941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
/* 1ud+~y$K  
**SiteFileFetch.java Jx:t(oUR+  
*/ 0M'[|ci d|  
package NetFox; VGVZ`|  
import java.io.*; [CBhipoc  
import java.net.*; QBNnvg4v  
b~1]}9TJ  
g@va@*|~d  
public class SiteFileFetch extends Thread { 0!:1o61  
[`_ZlC  
JMUk=p<\  
SiteInfoBean siteInfoBean = null; //文件信息Bean B4<W%lm  
long[] nStartPos; //开始位置 '>}dqp{Wr  
long[] nEndPos; //结束位置 $8{|25 *E  
FileSplitterFetch[] fileSplitterFetch; //子线程对象 QEavbh^S  
long nFileLength; //文件长度 @-~ )M_  
boolean bFirst = true; //是否第一次取文件 Qe&K  
boolean bStop = false; //停止标志 scff WqEo  
File tmpFile; //文件下载的临时信息 4TBK:Vm5  
DataOutputStream output; //输出到文件的输出流 (&w'"-`  
lYS+EVcR  
//负责整个文件的抓取,控制内部线程(FileSplitterFetch类) me#?1r  
public SiteFileFetch(SiteInfoBean bean) throws IOException Z=B6fu*  
{ fcuU,A  
siteInfoBean = bean; VPKoBJ&  
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath())); |b@H]c;"  
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info"); fVU9?^0/)9  
if(tmpFile.exists ()) wz,T7L  
{ \uumNpB*n  
bFirst = false; f?ImQYqP  
read_nPos(); T4OH,^J  
} = }&@XRLJ  
else ]y4(WG;:  
{ Bc/'LI.%  
nStartPos = new long[bean.getNSplitter()]; M<A*{@4$w&  
nEndPos = new long[bean.getNSplitter()]; "71,vUW  
} Ag>E%N  
A?DgeSm  
fjE  
urlwn*!^s  
} n9;z=   
p m4g),s  
\WDL?(G<  
public void run() $Vi[195]2  
{ T,Bu5:@#  
//获得文件长度 =aWj+ggd@  
//分割文件 [|=#~(yYQ  
//实例FileSplitterFetch $#cZJ@;]  
//启动FileSplitterFetch线程 "k8Yc<`u  
//等待子线程返回 b.`<T "y  
try{ ;{n@hM*O  
if(bFirst) U5 `h  
{ GAZTCkB"  
nFileLength = getFileSize(); [3yzVcr~4  
if(nFileLength == -1) 4k HFfc  
{ ad\?@>[ I  
System.err.println("File Length is not known!"); 2 kOFyD  
} -:hiLZJ7-  
else if(nFileLength == -2) n~1'M/wh  
{ LDj'L~H  
System.err.println("File is not access!"); ElAho3 W  
} I^M %+\  
else q(i^sE[y  
{ P9Gjsu #  
for(int i=0;i<nStartPos.length;i++) 73-*| @6  
{ "l-L-sc,  
nStartPos = (long)(i*(nFileLength/nStartPos.length)); (1 "unP-  
} N2?o6)  
for(int i=0;i<nEndPos.length-1;i++) Vvth,  
{ }Htnhom0n  
nEndPos = nStartPos[i+1]; |Ef\B] Ns  
} n21Pfig  
nEndPos[nEndPos.length-1] = nFileLength; s`j QX\{  
} 4(VVEe  
} ho1Mo  
vhw"Nl  
A@8Ot-t:\2  
//启动子线程 &C~R*  
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /Hox]r]'e  
for(int i=0;i<nStartPos.length;i++) I)xB I~x  
{ oD$8(  
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r/X4Hy0!lT  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |ZEZ@y^  
nStartPos,nEndPos,i); S$CO T)7  
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z7[TgL7  
fileSplitterFetch.start(); K[wOK  
} |x2 +O  
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1'skCR|!<  
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _RLx;Tn)L  
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", HF9\SVR B  
nEndPos = " + nFileLength); vybQ}dscn  
// fileSplitterFetch[nPos.length-1].start(); y Iab3/#`  
9uXuV$.  
IETdL{`~  
//等待子线程结束 q P<n<  
//int count = 0; Sv*@3x  
//是否结束while循环 ISQC{K']J  
boolean breakWhile = false; Kn9O=?Xh;  
uS9:cdH  
~R;9a"nr  
while(!bStop) AML8.wJ  
{ 16iymiLz&  
write_nPos(); !Gv*iWg  
Utility.sleep(500); _(CuuP$`I  
breakWhile = true; /jR]sC)xs  
i[:S *`@S  
1E(~x;*)  
for(int i=0;i<nStartPos.length;i++) N30w^W&  
{ ]r #YU0  
if(!fileSplitterFetch.bDownOver) g$&uD  
{ -hM nA)+  
breakWhile = false; }E01B_T9z  
break; XA cpLj]  
} ep"YGx  
} UbBo#(TZ)  
if(breakWhile) ;z6Gk&?  
break; JvA6kw,  
omxBd#;F$  
T&?0hSYt  
//count++; #n=b*.  
//if(count>4) br!:g]Vh  
// siteStop(); OL,3Jh% x  
} DzZ)a E  
G2FP|mf,  
U Ox$Xwp5&  
System.err.println("文件下载结束!"); -Jo8jE~>V  
} -IBf;"8f  
catch(Exception e){e.printStackTrace ();} Sm(QgZO[4  
} _$<Q$P6y  
M`W%nvEDE  
'Ii%/ Ob!  
//获得文件长度 (Bta vE  
public long getFileSize() s]=s2.=  
{ 3xhv~be  
int nFileLength = -1; !B=Oc!e=K  
try{ ;WQ@dC  
URL url = new URL(siteInfoBean.getSSiteURL()); "J0,SFu:  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t@GPB]3[  
httpConnection.setRequestProperty("User-Agent","NetFox"); A#s`!SNv  
x\=2D<@az  
IAr  
int responseCode=httpConnection.getResponseCode(); HaP0;9q  
if(responseCode>=400) {HV$hU+_)Q  
{ SZOcFmC?  
processErrorCode(responseCode); :n3)vK   
return -2; //-2 represent access is error 8S&Kf>D  
} q!iMc  
KRS_6G],{  
],*^wQ   
String sHeader; zNE"5  
;().  
*7"R[!9  
for(int i=1;;i++) > ,L'A;c}  
{ Oeo:V"  
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $}d| ~q\  
//Utility.log(in.readLine()); Onr#p4UT  
sHeader=httpConnection.getHeaderFieldKey(i); Luxo,Ve  
if(sHeader!=null) U D9&k^  
{ Kt WG2  
if(sHeader.equals("Content-Length")) ]w _,0q  
{ 1Aq*|JSk(  
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); )7mX]@  
break; >wK ^W{  
} r7tN(2;5  
} SrV+Ox  
else [\o+I:,}wi  
break; h&7]Bp  
} &Mset^o  
} N0be=IO5#  
catch(IOException e){e.printStackTrace ();} -e=p*7']  
catch(Exception e){e.printStackTrace ();} _VU/j9<+  
,}M@Am0~  
ETP}mo  
Utility.log(nFileLength); ({3hX"C@Q  
"7R"(.~>  
=RR225  
return nFileLength; @l9qH1  
} 0NLoqq  
_C9*M6IU  
KlgPDV9mg  
//保存下载信息(文件指针位置) e&dE>m  
private void write_nPos() QN[-XQ>Xt  
{ )hH9VGZq(  
try{ I At;?4  
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?^i$} .%W  
output.writeInt(nStartPos.length); g-=)RIwm  
for(int i=0;i<nStartPos.length;i++) :$&%Pxm  
{ $tyF(RybG  
// output.writeLong(nPos); +w Oa  
output.writeLong(fileSplitterFetch.nStartPos); ,jWMJ0X/N=  
output.writeLong(fileSplitterFetch.nEndPos); t&UPU&tY  
} /#Y)nyE  
output.close(); pv2_A   
} . xT8@]  
catch(IOException e){e.printStackTrace ();} s)$N&0\  
catch(Exception e){e.printStackTrace ();} e";r_J3w  
} U;n$  
[GeJn\C_?  
T>(nc"(  
//读取保存的下载信息(文件指针位置) .I{b]6  
private void read_nPos() ?45kN=%*s  
{ ScrEtN  
try{ 6JWCB9$4  
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k%\_UYa  
int nCount = input.readInt(); **rA/*Oc  
nStartPos = new long[nCount]; sDnHd9v<?t  
nEndPos = new long[nCount]; &sL(|>N  
for(int i=0;i<nStartPos.length;i++) @;}bBHQz{p  
{ eqcV70E8cK  
nStartPos = input.readLong(); %dTkw+J  
nEndPos = input.readLong(); 66<3zadJZU  
} SCk2D!u  
input.close(); l-"c-2-!  
} aH)$#6${Ap  
catch(IOException e){e.printStackTrace ();} nAn/Vu  
catch(Exception e){e.printStackTrace ();} @Md%gEh;&  
} ]=p@1  
'iO?M'0gE#  
&~P5 [[Q  
private void processErrorCode(int nErrorCode) G#/}_P  
{ $ WAFr  
System.err.println("Error Code : " + nErrorCode); 8P r H"pI  
} @ NGK2J  
>W"gr]R<  
Ec| Gom?  
//停止文件下载 q10gKVJum  
public void siteStop() V,bfD3S3  
{ THirh6  
bStop = true; b:.aZ7+4  
for(int i=0;i<nStartPos.length;i++) P0J3ci}^  
fileSplitterFetch.splitterStop(); HlqvXt\  
Ktg{-Xl  
I0 a,mO;m  
} v8"plx=3  
} 8YC\Bw  
//负责部分文件的抓取 >ir'v5  
**FileSplitterFetch.java u2 a U0k:  
*/ FR9<$  
package NetFox; 3*$A;%q  
@'U9*:}U  
5Qhu5~,K  
import java.io.*;  ~dfc  
import java.net.*; t>|Y-i3cb  
Z]l<,m  
{hB7F"S  
public class FileSplitterFetch extends Thread { <}-[9fW  
Pg" uisT#>  
brJ _q0@  
String sURL; //File URL vz:P 2TkM  
long nStartPos; //File Snippet Start Position Ed9ynJ~)X  
long nEndPos; //File Snippet End Position W HO;;j  
int nThreadID; //Thread's ID }l&Uh &B`  
boolean bDownOver = false; //Downing is over Vh^fbv`?  
boolean bStop = false; //Stop identical yfeX=h  
FileAccessI fileAccessI = null; //File Access interface )n 1b  
\B"5 Kp<  
Z<ozANbk  
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oK&LYlU  
{ c%v[p8 %  
this.sURL = sURL; T1hr5V<U  
this.nStartPos = nStart; ~U`oew  
this.nEndPos = nEnd; B" TZ8(<  
nThreadID = id; k|Vq-w  
fileAccessI = new FileAccessI(sName,nStartPos);//定位 / <WB%O  
} / ]_T  
y0>asl  
^RytBwzKM  
public void run() Rk.YnA_J6  
{ o^;$-O!/  
while(nStartPos < nEndPos && !bStop) 6H67$?jMyJ  
{ <jF]SN  
$.kP7!`:,  
yC !`6$  
try{ wXp A1,i  
URL url = new URL(sURL); '/U[ ui0{  
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~n%~ Z|mMF  
httpConnection.setRequestProperty("User-Agent","NetFox"); xaSvjc\  
String sProperty = "bytes="+nStartPos+"-"; <y=VDb/  
httpConnection.setRequestProperty("RANGE",sProperty); `,d*>  
Utility.log(sProperty); X=_pQ+j`^  
aYr?J Ol  
02:]  
InputStream input = httpConnection.getInputStream(); E%OY7zf`%  
//logResponseHead(httpConnection); e>~g!S}G  
G$pTTT6#  
$,q~q^0  
byte[] b = new byte[1024]; Htn=h~U`z  
int nRead; jW*|Mu>2  
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TjxZ-qw<  
{ %`%oupqm+  
nStartPos += fileAccessI.write(b,0,nRead); !"/]<OQ   
//if(nThreadID == 1) 3^ ~M7=k  
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); By{zX,6'  
} A<l8CWv[  
}]_/:KUt  
aAZS^S4v  
Utility.log("Thread " + nThreadID + " is over!"); r=P)iE:  
bDownOver = true; l T~RH0L  
//nPos = fileAccessI.write (b,0,nRead); r2}u\U4>  
} =; Gw=m(  
catch(Exception e){e.printStackTrace ();} Gm;)Om_  
} Aifc0P-H  
} \Km!#:  
e5KsKzu a  
$X8(OS5d'  
//打印回应的头信息 ,#[0As29u  
public void logResponseHead(HttpURLConnection con) W[BZ/   
{ )=l~XV  
for(int i=1;;i++) "a))TV%N  
{ 1oD,E!+^d  
String header=con.getHeaderFieldKey(i); E8gXa-hv  
if(header!=null) B*btt+6  
//responseHeaders.put(header,httpConnection.getHeaderField(header)); _#@n^c  
Utility.log(header+" : "+con.getHeaderField(header)); k `JP  
else ntbl0Sk  
break; hc OT+L>  
} L;zwqdI  
} k8H@0p  
{Vw+~8  
CsHHJgx  
public void splitterStop() r_nB-\  
{ Qb<i,`SN  
bStop = true; 's>   
} &5puGnTZ  
[P.M>"c\  
j#QJ5(#  
} P8!ON=  
Ix@rn  
/5A um ?~  
/* eygmhaE  
**FileAccess.java +\g/KbV7  
*//文件访问(定位,写) X{4jyi-<  
package NetFox; /a.4atb0  
import java.io.*; ?q a  
't:$Lx  
!z">aIj\6  
public class FileAccessI implements Serializable{ G2 A#&86J{  
_DsA<SJ]  
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }5c%v1  
RandomAccessFile oSavedFile; i!g}PbC[  
long nPos; r09gB#K4  
873$EiyXR  
]j> W9n?  
public FileAccessI() throws IOException hkV;(Fr&z  
{ 0WT]fY?IS  
this("",0); a(AKVk\  
} 8* 7t1$  
.4on7<-a  
0_'(w;!wq:  
public FileAccessI(String sName,long nPos) throws IOException m,}0p  
{ MU6|>{  
oSavedFile = new RandomAccessFile(sName,"rw"); Zjqa n  
this.nPos = nPos; )!6JSMS  
oSavedFile.seek(nPos); <T]%Gg8  
} },58B  
0K/Pth"*  
(:9yeP1  
public synchronized int write(byte[] b,int nStart,int nLen) k(LZ,WSR  
{ HJ#3wk"W  
int n = -1; ,/0Q($oz  
try{ $A~UA  
oSavedFile.write(b,nStart,nLen); zVN/|[KP4  
n = nLen; GL;@heP  
} y/=:F=H@w  
catch(IOException e) :})(@.H  
{ Z] ?Tx2|7  
e.printStackTrace (); N(i%Oxp1  
} .Zo%6[X  
\:]  
 x{K^u"  
return n; hojP3 [  
} ,b[}22  
$!Z><&^/  
l{b<rUh5W  
} s18o,Zs'  
lGrp^  
;:<z hO  
/* 8VG6~>ux'>  
**SiteInfoBean.java 3 #GZ6:rVJ  
*/ & \<!{Y<'  
package NetFox; oh*Hzb  
MTBHFjXO  
@ig'CF%(  
public class SiteInfoBean { _N8Tu~lqV  
m]H[$ Q  
vTnrSNdSE  
private String sSiteURL; //Site's URL x)evjX=q  
private String sFilePath; //Saved File's Path A8,9^cQ]  
private String sFileName; //Saved File's Name M)v\7a  
private int nSplitter; //Count of Splited Downloading File ++O L&n  
OJ#eh w<  
j,<3[  
public SiteInfoBean() W,sU5sjA  
{//nSplitter的缺省值为5 D5]AL5=Xt2  
//default value of nSplitter is 5 -64@}Ts*?  
this("","","",5); /<[S> ;!kr  
} &6]+a4  
~K'e}<-G  
feJzX*u  
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9Z?P/ o  
{ M:t!g %  
sSiteURL= sURL; l^`& Tnzv  
sFilePath = sPath; `Fn"%P!  
sFileName = sName; Q` ?+w+y7  
this.nSplitter = nSpiltter; 'iQ  
&d,chb (  
~nit~ ;  
} `As| MYv  
D$ X9xtT  
:LE0_ .  
public String getSSiteURL() lKVy{X 3]*  
{ j@chSk"K  
return sSiteURL; ~kDR9s7  
} '8%pEl^  
+Dvdv<+  
2Y~UeJ_\Lq  
public void setSSiteURL(String value) ^b{-y  
{ Kmy'z  
sSiteURL = value; P9d%80(b4  
} mM`zA%=  
n oWjZ  
}E o\=>l7  
public String getSFilePath() PK&3nXF%4  
{ C\-Abq c  
return sFilePath; FEOr'H<3x  
} L >* F8|g  
+SM&_b  
9gu$vF]9!  
public void setSFilePath(String value) w$5~'Cbi  
{ :+ASZE.  
sFilePath = value; U2Uf69R  
} z@70{*  
bxxazsj^  
A%Ov.~&\G  
public String getSFileName() O &/9wi>!q  
{ r'TxYM-R  
return sFileName; [_$r-FA  
} :eK(9o  
l ~bjNhk  
)7X+T'?%  
public void setSFileName(String value) |AosZeO_  
{ ~Onj| w7  
sFileName = value; 72i ]`   
} -|1H-[Y(  
w@K4u{|  
W|~Jl7hs8Q  
public int getNSplitter() #=}dv8  
{ 4blw9x N  
return nSplitter; It5U=PU  
} M lv  
KOQiX?'  
1\'?.  
public void setNSplitter(int nCount) R1!F mZW8  
{ C]X:@^Hy  
nSplitter = nCount; "7w~0?}  
} .,-,@ZK  
} .2K4<UOAbm  
a'NxsByG]s  
"ITC P<+  
/* ~RdD6V  
**Utility.java '7'*+sgi$  
*/ Mx-? &  
package NetFox; ,H_b@$]n8  
7m4gGkX#r  
4yZ'+\ +I  
public class Utility { s!lLdR[g  
For`rfR  
|E& F e8  
public Utility() g431+O0K1  
{ \t pJ   
PZT]H?  
rP5&&Hso  
}  <>|&%gmz  
DGs=.U-=e  
//线程睡眠 4t C-msTf  
public static void sleep(int nSecond) A-=B#UF  
{ `.MY" g9  
try{ ]"ZL<?3g  
Thread.sleep(nSecond); .o27uB.  
} c `[,>  
catch(Exception e) V6c>1nZ  
{ a {4Wg:  
e.printStackTrace (); 9s#Q[\B!  
} ^#6"d+lp  
} &Zxo\[lP  
|b BA0.yS  
//日志 4qd =]i  
public static void log(String sMsg) )td?t.4  
{ # NoY}*  
System.err.println(sMsg); )A@ }mIs"  
} Ok0zgi  
NmH1*w<A  
g6s&nH`Z2  
public static void log(int sMsg) )2nx5 "  
{ D.!ay>o0#  
System.err.println(sMsg); 5B|&+7dCw  
} A`5/u"]*D  
} WfdM~k\  
?{)sdJe  
/Zzb7bHLK  
/* IIn sq  
**TestMethod.java v+), uj  
*/ 6w?l I  
package NetFox; +qWrm |O]  
~PTqR2x  
gv6}GE  
public class TestMethod { Zb \E!>V  
vU4Gw4  
0mb|JoE(  
public TestMethod() tny^sG/'  
{ ///xx/weblogic60b2_win.exe  L+=pEk_  
try{ \! *3bR  
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @Sik~Mm_h  
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $] gwaJ:  
SiteFileFetch fileFetch = new SiteFileFetch(bean); p)x*uqSd  
fileFetch.start(); H'2J!/V  
} ,qj1"e  
catch(Exception e){e.printStackTrace ();} n#US4&uT4A  
3 L:s5  
I^u$H&  
} nDFF,ge;a#  
ms(Z1ix^  
o4[  
public static void main(String[] args) +zl2| '  
{ h/LlH9S:!  
new TestMethod(); ^(Y}j8sj  
} \68x]q[  
} Dc1tND$X3g  
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
温馨提示:欢迎交流讨论,请勿纯表情、纯引用!
认证码:
验证问题:
3+5=?,请输入中文答案:八 正确答案:八