http断点续传简单实现（java)

亚文隆

级别: 经院学前班

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

只看楼主更多操作楼层直达

0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); .P#t"oW}
} uuQsK. S
for(int i=0;i<nEndPos.length-1;i++) _ h/:r1
{ =)}Yw)
nEndPos = nStartPos[i+1]; 5/R ~<z
} z))rk vL%
nEndPos[nEndPos.length-1] = nFileLength; N)/7j7c~;
} tzY?LX[3
} @1~cPt
LJA uTg
9"?;H%.
//启动子线程 $F1Am%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +7{8T{
for(int i=0;i<nStartPos.length;i++) oT|:gih5
{ @~&|BvK% \
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1:RK~_E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tr58J%Mu
nStartPos,nEndPos,i); m=TZfa^r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F$ckW'V
fileSplitterFetch.start(); NtmmPJ|5
} qOAP_\@T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), dt0(04
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); #r,!-;^'p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E5?$=cL?
nEndPos = " + nFileLength); r`$P60,@C
// fileSplitterFetch[nPos.length-1].start(); c_t7<
U] P{~
Fr-Vq=j&
//等待子线程结束 k(xB%>ns
//int count = 0; %XQJ!sC`
//是否结束while循环 {8 &=t8,c
boolean breakWhile = false; dkW7k^g
pgW^hj\
%jJIR88
while(!bStop) |tC= j.
{ QRx9;!~b}
write_nPos(); N;DE,[:<
Utility.sleep(500); fymmAfaR
breakWhile = true; c& $[a%s
*to#ZMR;!
i*8j|
for(int i=0;i<nStartPos.length;i++) l3+G]C&<
{ K+d{R=s^
if(!fileSplitterFetch.bDownOver) (:^YfG~e
{ b81cq,
breakWhile = false; (Q.tH
break; sX]gL
} ,kUg"\_k
} ,4k3C#!.i
if(breakWhile) @vL0gzE?nB
break; |"[;0)dw^
VtMnLFMw
cYvt!M\ed
//count++; r?|(t?
//if(count>4) 1d$wP$
// siteStop(); W)^%/lAh
} b~{nS,_Rn
q,OCA\
*,)1Dcv(
System.err.println("文件下载结束！"); {{)pb>E
} &XW~l>!+
catch(Exception e){e.printStackTrace ();} 5=fS^]- F
} WR u/7$8
D&=+PAX
nm)/BK
//获得文件长度 JEK_W<BD
public long getFileSize() <<V"4 C2
{ '3~m},0
int nFileLength = -1; O|+$9#,
try{ VbNN1'a-
URL url = new URL(siteInfoBean.getSSiteURL()); F0"("4h:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -X3CrW
httpConnection.setRequestProperty("User-Agent","NetFox"); UR(i_T&w
t0za%q!fK<
xiL+s-
int responseCode=httpConnection.getResponseCode(); sGh TP/
if(responseCode>=400) /`t}5U>S_
{ 0X$2~jV>
processErrorCode(responseCode); =iB$4d2
return -2; //-2 represent access is error ;Zc0imYL
} EztuVe
k2.\1}\
*^XMf
String sHeader; e.Jaq^Gw|
i>C%[dk9
_n4_;0
for(int i=1;;i++) 99%R/m
{ C' WX$!$d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =$T[
//Utility.log(in.readLine()); TH55@1W,[
sHeader=httpConnection.getHeaderFieldKey(i); ?m9=Me
if(sHeader!=null) ,|]k4F
{ I,"q:QS+
if(sHeader.equals("Content-Length")) b2RW=m-
{ 9!0-~,o
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FE:}D;$
break; ^W`RBrJay
} xgtx5tg
} i[wnG)
else 3Vk\iJ
break; !Q,Dzv"7
} C0khG9,BL
} Y=H_U$
catch(IOException e){e.printStackTrace ();} Q=Q&\.<
catch(Exception e){e.printStackTrace ();} -Vs;4-B{9
Hq&MePl[
:*R+ee,&-
Utility.log(nFileLength); A+}O~,mxP8
|x=(}g
,#9i=gp
return nFileLength; UMMGT6s,E8
} IR&b2FTcU
6BZi4:PDx
L+mHeS l
//保存下载信息（文件指针位置） #KuBEHr
private void write_nPos() H`yUSB IP
{ T hVq5
try{ _bv9/#tR
output = new DataOutputStream(new FileOutputStream(tmpFile)); z uo:yaO
output.writeInt(nStartPos.length); B`vC>
for(int i=0;i<nStartPos.length;i++) !Q}Bz*Y
{ 3ly]DTbz
// output.writeLong(nPos); P%d3fFzK
output.writeLong(fileSplitterFetch.nStartPos); .x}xa
output.writeLong(fileSplitterFetch.nEndPos); 1suP7o A;
} Mp^G7JY,
output.close(); kX*.BZI}C
} !<F5W<V
catch(IOException e){e.printStackTrace ();} .3>q3sS
catch(Exception e){e.printStackTrace ();} e:.D^GFi
} WopA7J,
d"a\`#
9)n3f^,Oj*
//读取保存的下载信息（文件指针位置） aU#r`D@0
private void read_nPos() !,sQB_09C
{ 'oM=ZU8wo
try{ Wd7qpWItjQ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); m!(dk]
int nCount = input.readInt(); &#9HV
nStartPos = new long[nCount]; )Ofwfypc
nEndPos = new long[nCount]; DZ:$p.
for(int i=0;i<nStartPos.length;i++) +S1h~@c:B
{ 3GMrdG?Y
nStartPos = input.readLong(); p77=~s
nEndPos = input.readLong(); '*`1uomeo
} zQB1C
input.close(); T:!H^
} sdKm@p|/|
catch(IOException e){e.printStackTrace ();} [vnxp/v/<
catch(Exception e){e.printStackTrace ();} "y ;0}9]n1
} jS|jPk|I.
,o0[^-b<
7{VN27Fa_
private void processErrorCode(int nErrorCode) _Om5wp=:
{ R-2Abyts2
System.err.println("Error Code : " + nErrorCode); 0OnqKgf
} }_Y\6fcd
a,:Nlr3
Sg(\+j=
//停止文件下载 51;Bc[)%
public void siteStop() eMP0BS"
{ Bi0&F1ZC!
bStop = true; v5FfxDvw
for(int i=0;i<nStartPos.length;i++) mAe)Hy %
fileSplitterFetch.splitterStop(); \=(U tro
bE jQMlb
bOr6"nn
} =7S\-{
} ;9)=~)
//负责部分文件的抓取 _z#S8Y
**FileSplitterFetch.java mhNgXp)_56
*/ >^v,,R8j
package NetFox; }To-c'
B"t4{1/
z:08;}t
import java.io.*; 1NAtg*`
import java.net.*; `R-VJR 2"
)$O'L7In&
3)l<'~"z<
public class FileSplitterFetch extends Thread { o%h[o9i
#BI6+rfv|
Q:]v4/MT
String sURL; //File URL }dEf |6_
long nStartPos; //File Snippet Start Position +@do<2l]
long nEndPos; //File Snippet End Position `Tr !Gj_
int nThreadID; //Thread's ID 3B4C@ {
boolean bDownOver = false; //Downing is over H$,wg!kY!
boolean bStop = false; //Stop identical ~S0T+4$
FileAccessI fileAccessI = null; //File Access interface 1Nz#,IdQ
d81[hT}q
h|EHK!<"8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x`K"1E{2
{ rWp+kV[Ec>
this.sURL = sURL; :ZXaJ!
this.nStartPos = nStart; h~#.s*0.F
this.nEndPos = nEnd; Hc\oR(L
nThreadID = id; irn }.e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~b9fk)z!
} .zJZ*\2ob
mvyOwM
sw,p6T[
public void run() FuP~_ E~
{ = Fwzm^}6
while(nStartPos < nEndPos && !bStop) ka:wD?>1i
{ _!o0bYD
v2>Dn=V
gv,%5r0YOw
try{ KwxJ{$|xH
URL url = new URL(sURL); )u307Lg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +4k4z:<n
httpConnection.setRequestProperty("User-Agent","NetFox"); (2/i1)Cq
String sProperty = "bytes="+nStartPos+"-"; }G<A$*L1
httpConnection.setRequestProperty("RANGE",sProperty); T>v`UN Bl]
Utility.log(sProperty); #o(@S{(NZ
+F^X1
mXUe/*r0T
InputStream input = httpConnection.getInputStream(); l^v,X%{Iz
//logResponseHead(httpConnection); lH>6;sE
9YwS"~Q =w
C+-sf
byte[] b = new byte[1024]; q94*2@KV
int nRead; n:JG+1I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) i]0$7s9!
{ LhKUZX,P8
nStartPos += fileAccessI.write(b,0,nRead); B_0]$D0 ^
//if(nThreadID == 1) <-!'V,c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )umW-A
} h6e,w$IL
u6/;=]0
0Pg@%>yb~
Utility.log("Thread " + nThreadID + " is over!"); :LD+B1$y
bDownOver = true; ^bXCYkx
//nPos = fileAccessI.write (b,0,nRead); R-\"^BV#Z
} SXmh@a"*\
catch(Exception e){e.printStackTrace ();} 4$4n9`odE
} .u;'eVH)a}
} ^I!gteU;
iBqIV
/gE9 W
//打印回应的头信息 w1t0X{
public void logResponseHead(HttpURLConnection con) !)uXCg9U
{ D o!]t7Y$
for(int i=1;;i++) Q8bn|#`
{ +fq;o8q
String header=con.getHeaderFieldKey(i); Y67i\U>?
if(header!=null) %* @hS`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p;{w0uld"
Utility.log(header+" : "+con.getHeaderField(header)); P/8z
else SSr2K
break; 15!b]':
} `wNJ*`
} i$4lBy_2
A Zv| |8p
"C9.pdP\8
public void splitterStop() "'6R|<u=:
{ 2$oGy
bStop = true; CIf""gL9
} Xd9<`gu
W7 9.,#
KnYHjJa
} z';h5GNd>z
$dHD
w7_2JS
/* ,9/s`o
**FileAccess.java +F6R@@rWr
*//文件访问(定位，写) A*3R@G*h
package NetFox; 8hvh xp
import java.io.*; X[o"9O|<
l,1.6
bl;v^HR0)
public class FileAccessI implements Serializable{ c# WIB 4
)hK1W\5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 s B!2't
RandomAccessFile oSavedFile; w3peG^4D_
long nPos; 2&U<Wiu\}
n0ls a@l
r#K"d
public FileAccessI() throws IOException 58_aI?~>>
{ ki|w?0s
this("",0); j_~lc,+m
} '#x<Fo~hT
Q$DF3[NC
k3t2{=&'&x
public FileAccessI(String sName,long nPos) throws IOException c9;oB|8|
{ gc{5/U9H*
oSavedFile = new RandomAccessFile(sName,"rw"); DX#F]8bWl
this.nPos = nPos; %q,^A+=
oSavedFile.seek(nPos); @7<m.?A!
} >eaK@u-'0
JZrUl^8E
v4wXa:CJ
public synchronized int write(byte[] b,int nStart,int nLen) N_>}UhZ
{ 1oIu~f{`
int n = -1; wenJ(0L|
try{ %uhhQ<zs%
oSavedFile.write(b,nStart,nLen); RlTVx:
n = nLen; )ur&Mnmm
} X+XbIbUuL
catch(IOException e) nzORG
{ ecy41y'~:
e.printStackTrace (); &,@wLy^T
} 5Ai$1'*p
J'y*>dW
t9 m],aH
return n; esQRg~aCGy
} tc<t%]c
)?PRG=
9CTvG zkw
} $U/_8^6B0
!#8=tO
},LW@Z}
/* K1>(Fs$
**SiteInfoBean.java Vl+,OBy
*/ cZXra(AD
package NetFox; !4G<&hvb
H=k*;'
v;@-bED(Qs
public class SiteInfoBean { `+0)dTA(g$
yLlAK,5P0o
+,$"%C
private String sSiteURL; //Site's URL mg^\"GC*8
private String sFilePath; //Saved File's Path #`H^8/!e
private String sFileName; //Saved File's Name gJ>HFid_C
private int nSplitter; //Count of Splited Downloading File Af"vSL
cZ~\jpK
>ak53Ij$
public SiteInfoBean() u +OfUBrf
{//nSplitter的缺省值为5 v{2Vg
//default value of nSplitter is 5 1"CbuV 6
this("","","",5); %U)M?UNjw
} i@ avm7
L~FE;*>7
g#ONtY@*U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) I:aG(8Bi)H
{ 9jwo f}OU
sSiteURL= sURL; H;n(qBSB
sFilePath = sPath; S[ ,r.+
sFileName = sName; C&'Y@GE5
this.nSplitter = nSpiltter; lEC58`Ws
P&Q 5ZQb
3It'!R8$
} 4n@, p0
gZs8BKO
qlg~W/
public String getSSiteURL() {9Op{bZ
{ :I}_
return sSiteURL; %R{clbbbn
} -h8!O+7 .
}?Y+GT"E
VmB/X))
public void setSSiteURL(String value) lA<IcW
{ W$Bx?}x($
sSiteURL = value; P( W8XC
} o;JBe"1
.W&rcqy
<ZNa`
public String getSFilePath() m H'jr$ ?
{ STmCj
return sFilePath; +:[dviyPt
} F#^.L|d4
;D[b25
jL)aU> kN
public void setSFilePath(String value) n.y72-&v
{ E}qeh"sJt
sFilePath = value; pz^"~0o5
} 2Xgw7` !L
>}/"gx
+* )Qi)
public String getSFileName() Q_#X*I
{ 3Pp*ID
return sFileName; 1W HR;!u
} ? F fw'O
$/45*
!{SU G+.2
public void setSFileName(String value) 0r=Lilu{q
{ s/Wg^(&M
sFileName = value; r/L3j0
} !U/:!e`N
(.!q~G
N1(}3O
public int getNSplitter() SJ7>*Sa(u$
{ Z-H Kdv!d
return nSplitter; u6jJf@!ws
} (s{%XB:K
Af0E_
0tB9X9:,
public void setNSplitter(int nCount) Zk}e?Grc
{ ?#D@e5Wf
nSplitter = nCount; 2#1FI0,Pa*
} $X~=M_W
} =W !m`
lLtC9:
^O\tN\g;c
/* \{+7`4g
**Utility.java m$hSL4N
*/ O,JthlAV4
package NetFox; =OO_TPEZ
uD:O[H-x
r:Cad0xj;^
public class Utility { Q:VD2<2
,bmTBZV
9LJ/m\bi
public Utility() nhXa&Nro
{ rmQGzQnun
P!YT{}
G';oM;~/|
} ieS5*@^k
q}BQu@'H
//线程睡眠 ~w[zX4@
public static void sleep(int nSecond) ",8h>eEWK
{ ;{Z2i%
try{ A7_*zR@
Thread.sleep(nSecond); ,%nmCetD@
} n7<<}wcV
catch(Exception e) "TjR]jnV(
{ /'VCJjzZ
e.printStackTrace (); ocgbBE
} ~T4=Id
} x5`q)!<&
JG}U,{7(
//日志 xI:;%5{LN
public static void log(String sMsg) <JH0 &
{ "l +Jx|h\
System.err.println(sMsg); A7b7IM[
} )cs y^-qw
QTn-n)AE
~Nc]`95
public static void log(int sMsg) "hlIGJ?_=
{ oHi&Z$#!n
System.err.println(sMsg); `(o1&
} dnIBAe
} X?7$JV-:
U;V. +onv
[sKdIw_
/* (vj2XiO^+
**TestMethod.java zLh ~x
*/ rX{|]M":T
package NetFox; =h_4TpDQ
^*{xTB57
@#Xzk?+
public class TestMethod { Ha+FH8rZ
D *LZ_
&aF_y_f\
public TestMethod() ]&G5/]f
{ ///xx/weblogic60b2_win.exe < m9O0
try{ 1;:2=8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); -ZyFUGd%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ([9h.M6v
SiteFileFetch fileFetch = new SiteFileFetch(bean); .PAkW2\#
fileFetch.start(); VJR'B={h
} s9E:6
catch(Exception e){e.printStackTrace ();} WVNQ}KY
M2zfN ru
dU&.gFw1
} H`Z4a N
#!`zU4&2
l E&hw
public static void main(String[] args) s*8hN*A/,
{ D 1hKjB&
new TestMethod(); 'Yd%Tb|*
} Q^p@ 1I
} MZd\.]G@
点击下载更多相关资料