http断点续传简单实现（java)

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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)); b9nTg
} m1bkY#\ U|
for(int i=0;i<nEndPos.length-1;i++) [g)HoR=&
{ j.=&qYc0"
nEndPos = nStartPos[i+1]; h</,p49gM
} ]R%[cr
nEndPos[nEndPos.length-1] = nFileLength; XhEZTg;
} Ckd j|
} 6z`l}<q
^m0nInH
O2xbHn4
//启动子线程 3dO~Na`S
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4eVQO%&2
for(int i=0;i<nStartPos.length;i++) [B~*88T
{ dfy]w4ETB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &/dYJv$[9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), mok94XuK)
nStartPos,nEndPos,i); o3b=)E
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /q1k)4?E
fileSplitterFetch.start(); YV%y KD
} eX`wQoV%
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }2xgm9j<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e={ ?d6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BD.&K_AW
nEndPos = " + nFileLength); arK(dg~S
// fileSplitterFetch[nPos.length-1].start(); 3Z0ez?p+5
4,g_$)
RE._Ov>
//等待子线程结束 z }3`9
//int count = 0; t@X{qm:%Z
//是否结束while循环 8'WoG]E_
boolean breakWhile = false; r+=%Ag
oYx4+xH/
Ml,~@} p
while(!bStop) --OAsbr
{ GVT| fE
write_nPos(); 6JgbJbUi
Utility.sleep(500); n4XEyCrD
breakWhile = true; hMCf| e.UY
#W$6[#7=I
d+45Y,|
for(int i=0;i<nStartPos.length;i++) ,#Pp_f<
{ )7c/i+FsC
if(!fileSplitterFetch.bDownOver) 2CMWJi
{ c1tM(]&
breakWhile = false; (N"9C+S}
break; a``/x_EZMn
} 5J-slNNCQ
} |@W|nbAfX
if(breakWhile) J,G/L!Bp
break; >//yvkZ9,
M{z&h>
u+lNcyp"MW
//count++; @[LM8 @:
//if(count>4) G^ShN45
// siteStop(); :3N6Ej
} V~#8lu7;
Tuz~T _M
|zbM$37?k
System.err.println("文件下载结束！"); *j~ObE_y
} F4NMq&_
catch(Exception e){e.printStackTrace ();} 'QSj-
} 7Y?59 [
_U|rTil
V=gu'~
//获得文件长度 (}RTHpD
public long getFileSize() lLur.f
{ 42f\]R,
int nFileLength = -1; TO&^%d
try{ |F4)&xN\
URL url = new URL(siteInfoBean.getSSiteURL()); !_q=r[D\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <<DPer2
httpConnection.setRequestProperty("User-Agent","NetFox"); yi8AzUW cW
v65]$%F?
!k<k]^Z\
int responseCode=httpConnection.getResponseCode(); vYybQ&E/
if(responseCode>=400) FwE<_hq//
{ v4qpE!W27~
processErrorCode(responseCode); :x,dYJm
return -2; //-2 represent access is error dUQ)&Hv
} %H[~V f?d
e/uLBZ
}#q0K
String sHeader; DzbcLg%:W
Xz?7x0)Z
!q~f;&rg
for(int i=1;;i++) 1! j^
{ hzk4SOT(
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xyP0haE
//Utility.log(in.readLine()); },=ORIB B:
sHeader=httpConnection.getHeaderFieldKey(i); u+9)B 6O1
if(sHeader!=null) 6<%b}q9Mo
{ ~Qd|.T
if(sHeader.equals("Content-Length")) au E8 ^|
{ ,V9r2QY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .?5~zet#;
break; vA{DF{S4
} }tW1\@ =
} wE-y4V e
else g)ofAG2
break; z5_jx&^Z
} \j<aFOT(
} : sG/
catch(IOException e){e.printStackTrace ();} l1.eAs5U
catch(Exception e){e.printStackTrace ();} 6P T)
a$EudD#+
r]'[qaP
Utility.log(nFileLength); |.b&\
nf-6[dg
Y>{%,d#s_
return nFileLength; E#A}2|7,g
} "!Nu A
_&N:%;9uD
*Z+U}QhHD6
//保存下载信息（文件指针位置） , {}S<^?]
private void write_nPos() |kF"p~s
{ T2A74>Nw
try{ 8.&P4u i
output = new DataOutputStream(new FileOutputStream(tmpFile)); /!_FE+
output.writeInt(nStartPos.length); J|@O4g
for(int i=0;i<nStartPos.length;i++) .zy2_3:
{ /uPMzl
// output.writeLong(nPos); #3O$B*gV6
output.writeLong(fileSplitterFetch.nStartPos); &gP1=P,!
output.writeLong(fileSplitterFetch.nEndPos); ;Za^).=
} sHPlNwyy
output.close(); lmIphOUoIw
} u`XZtF<vf
catch(IOException e){e.printStackTrace ();} gk}.LE
catch(Exception e){e.printStackTrace ();} LWxP}? =
} [B^V{nUBc
&Z}}9dd
pf#R]
//读取保存的下载信息（文件指针位置） Abpzf\F
private void read_nPos() kaRjv
{ *c(J4
try{ W6)XMl}n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); x&N@R?AG1
int nCount = input.readInt(); m;sYg
nStartPos = new long[nCount]; UZL-mF:)&
nEndPos = new long[nCount]; " ;o,D
for(int i=0;i<nStartPos.length;i++) @7sHFwtar?
{ ,D.@6bJW
nStartPos = input.readLong(); 2h)*
nEndPos = input.readLong(); .B!L+M< [
} 3!Mb<W.3
input.close(); - v=ndJ.
} 1`1Jn*|TI
catch(IOException e){e.printStackTrace ();} lrgvY>E0
catch(Exception e){e.printStackTrace ();} 6|Crc$4l
} "Z"`X3,-z
"2}n(8
Q@s G6iz
private void processErrorCode(int nErrorCode) )LL.fPic
{ ;`Sn66&
System.err.println("Error Code : " + nErrorCode); ?U,XyxN
} yn2k!2]&T<
m~@Lt~LZs
tbB.n
//停止文件下载 YCBUc<)
public void siteStop() >qdRqy)DC
{ +p-S36K~,7
bStop = true; RRtOBrIedI
for(int i=0;i<nStartPos.length;i++) km}E&ao
fileSplitterFetch.splitterStop(); ai)?RF
lC^?Jk[N
`J}FSUn\
} ` kZ"5}li
} gT|&tTS1@
//负责部分文件的抓取 L @8[.
**FileSplitterFetch.java c-[IgX e
*/ WWA!_
package NetFox; )IuwI#pm
Lf,C50
=/N0^
import java.io.*; =Q8$O 2TW
import java.net.*; YY$O"!."
hw&~OJeo
tY?evsVgz
public class FileSplitterFetch extends Thread { Zk #C!]=
} ejc
af/;Dr@
String sURL; //File URL >;X^+JH!)
long nStartPos; //File Snippet Start Position 7v(<<>
long nEndPos; //File Snippet End Position wHErF #xo
int nThreadID; //Thread's ID Z.0mX#
boolean bDownOver = false; //Downing is over zQtx!k=
boolean bStop = false; //Stop identical peU1 t:k?
FileAccessI fileAccessI = null; //File Access interface l 4cTN @E
6 wD
-:V2Dsr6;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException f q*V76F
{ 68!=`49r>
this.sURL = sURL; Z15b'^)?9
this.nStartPos = nStart; 4hV~ ir
this.nEndPos = nEnd; M5B?`mTl
nThreadID = id; lJ<( mVt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 N4,!b_1
} )eWg2w]
t2z@"e
1<f,>BQ+
public void run() ^^(4xHN
{ Xx=.;FYk
while(nStartPos < nEndPos && !bStop) GnW_^$Fs
{ 3q1u9`4;
V7>{,
<V*M%YWs
try{ YwF\
URL url = new URL(sURL); {qBbzBG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o(5 (]bJ
httpConnection.setRequestProperty("User-Agent","NetFox"); mvBUm-X
String sProperty = "bytes="+nStartPos+"-"; H{*R(S<I
httpConnection.setRequestProperty("RANGE",sProperty); _+nlm5
Utility.log(sProperty); o n?8l?iQ
b.v^:M
9,Ug
InputStream input = httpConnection.getInputStream(); (2%z9W
//logResponseHead(httpConnection); ?;Ge/~QU5
b%I2ig
.sbV<ulbc
byte[] b = new byte[1024]; M{~KT3c
int nRead; Fy]j33E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4Yl:1rz
{ AlT04H
nStartPos += fileAccessI.write(b,0,nRead); rxAb]~MMp
//if(nThreadID == 1) 1)h+xY
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p"/B3
} *mXs(u
mdIa`OZr
`@i!'h
Utility.log("Thread " + nThreadID + " is over!"); t>%J3S>'ZV
bDownOver = true; '|K408i
//nPos = fileAccessI.write (b,0,nRead); ~D\ V!
} :S{+|4pH
catch(Exception e){e.printStackTrace ();} nK|WzUtp
} ZIM 5$JdCv
} ?!kPW^gD
eMDraJv@
vh^,8pPy
//打印回应的头信息 VBI~U?0
public void logResponseHead(HttpURLConnection con) b$'}IWNV
{ a(`@u&]WZ
for(int i=1;;i++) i9k/X&V
{ .TetN}w
String header=con.getHeaderFieldKey(i); q/yL={H?
if(header!=null) Sf*b{6lcC
//responseHeaders.put(header,httpConnection.getHeaderField(header)); D.R 7#^.
Utility.log(header+" : "+con.getHeaderField(header)); E14Dq#L
else j]5bs*G
break; 2:l8RH!Y
} KZSvT{
} [!#<nY/C
GFBku^pi
4&([<gyR<
public void splitterStop() !5K9L(gqb
{ 9;u&,R
bStop = true; IXef}%1N?
} {z/Y~rf
'rQ>Z A_8
')>&:~
} %2D9]L2Up
ULkhTB
uDpCW}
/* \4OX]{
**FileAccess.java y6nPs6kR
*//文件访问(定位，写) ix]t>2r
package NetFox; .d>TU bR;
import java.io.*; wR=WS',
11(:#4Y,
qKg*/)sD(
public class FileAccessI implements Serializable{ 5L4{8X0X8
3KW4 ]qo~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 gK8{=A0c
RandomAccessFile oSavedFile; zn'F9rWx>
long nPos; P6ztP$M(
XNJPf) T
3B5GsI
public FileAccessI() throws IOException OWRT6R4v
{ G&HCOR!h
this("",0); 8=U0\<wT
} TZk.?@s5
6eh\-+=
2=PX1kI
public FileAccessI(String sName,long nPos) throws IOException tmJ-2
{ ^%?*u;uU%
oSavedFile = new RandomAccessFile(sName,"rw"); OF)G2>t
this.nPos = nPos; ;L458fYs
oSavedFile.seek(nPos); Gd8FXk,.!
} \'gb{JO
"NgfdLz
%cl=n!T
public synchronized int write(byte[] b,int nStart,int nLen) j%m9y_rg}
{ `'Af`u\R
int n = -1; )E.!jL:g
try{ rVE!mi]%
oSavedFile.write(b,nStart,nLen); Pn*+g!`
n = nLen; ROyG+dUy
} As;@T$G
catch(IOException e) 5QR=$?K
{ U2u\Q1
e.printStackTrace (); ^"e|)4_5\
} Is $I;`
^T#bla893
#ONad0T;
return n; .W#-Cl&n8
} Oist>A$Z
S}Q/CT?au
VM1`:1Z:$
} ebSG|F
TM1isZ
M6 W{mek
/* \L"Vx9xT
**SiteInfoBean.java +$-@8,F>
*/ o&GS;{Rs
package NetFox; G'5p/:
gxIGL-1M
:4f>S)m
public class SiteInfoBean { GEdWpYKS-`
\CP)$0j-&o
ok"v`76~f5
private String sSiteURL; //Site's URL [zO:[i 7
private String sFilePath; //Saved File's Path 9Q<8DMX^
private String sFileName; //Saved File's Name WPmH4L>T
private int nSplitter; //Count of Splited Downloading File ZPieL&uV`
zF9SZ#{a
'edd6yTd
public SiteInfoBean() RpAqnDX)
{//nSplitter的缺省值为5 L|wD2iw
//default value of nSplitter is 5 -_bnGY%,
this("","","",5); s\k4<d5
} H6Mqy}4W
E,S[3+
6V"|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 3++}4%w
{ R aVOZ=^-
sSiteURL= sURL; hmRnr=2N
sFilePath = sPath; =ZE]jmD4P
sFileName = sName; Df\~ ZWs!
this.nSplitter = nSpiltter; v-k~Q$7~
PgeC\#;9
-K 7jigac
} llCBqWn
b'!t\m
OlW|qj
public String getSSiteURL() ''{REFjK7
{ -VqZw&"
return sSiteURL; </UUvMf"
} f4JmY1)@
$)1i)/]9U
pSjJ u D
public void setSSiteURL(String value) 0]3 ,0s $}
{ hV(>}hb
sSiteURL = value; |Va*=@&6J
} U7)#9qS4
gn2*'_V~3
,N[N;Uoj
public String getSFilePath() [1-1^JY
{ w1aev
return sFilePath; F;4*,Ap
} {t.5cX"[
emhI1 *}
'pCZx9*c
public void setSFilePath(String value) k$u\\`i]oC
{ {:D8@jb[
sFilePath = value; |[)k5nUQ|
} PTU_<\
V`/E$a1&
UlG8c~p
public String getSFileName() =cwQG&as
{ qO;.{f
return sFileName; aC\O'KcH
} y /$Q5P+o
f<14-R=
g*]hmkYe9
public void setSFileName(String value) {|KFgQ'\
{ V`c"q.8
sFileName = value; -8HK_eQn
} Dl a }-A:
#\|Ac*>
6x'F0{U
public int getNSplitter() p?uk|C2
{ BBV"nm_(/
return nSplitter; Ic 5TtN~/>
} |fL|tkGEa
mH1T|UI
N\,[(LbA&
public void setNSplitter(int nCount) P3Wnso
{ :3J0Q
nSplitter = nCount; L701j.7"
} 50s1o{xwc
} o1kTB&E4B
'n:|D7t
Vu0d\l^$
/* zBQV2.@
**Utility.java wMW."gM|
*/ u|ph_?6o
package NetFox; 1zGD~[M
O$qxo &
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public class Utility { 8t1XZ
S55h}5Y
\;!}z3Ww
public Utility() J?wCqA
{ TANv)&,|9
i;flK*HOZ9
-w dbH`2Z"
} 9QQiIi$74U
Dias!$g
//线程睡眠 lm;Dy*|<
public static void sleep(int nSecond) {Jna' eS
{ R]h3a:ic
try{ b<\2j5
Thread.sleep(nSecond); ME0vXi
} ]9 JLu8GO
catch(Exception e) R)@2={fd}
{ -JEiwi,
e.printStackTrace (); J~]Y
} H;h$k]T
} oe'f?IY
%,1xOl4l
//日志 ]<3n;*8k?
public static void log(String sMsg) HzMr
{ 9{GEq@`7
System.err.println(sMsg); g"Tb\
} o2 ;
9-W3}4'e
R_4eME2LB
public static void log(int sMsg) qj7}]T_
{ Sl;[9l2
System.err.println(sMsg); Y&XO:jB
} 0h=}BCb+i
} VLfc6:Yg
t]CA!i`
y+aKk6(_W
/* W ZT) LYA
**TestMethod.java 6MD9DqD
*/ AoU Pq
package NetFox; fTOGW`s^
7DKTd^^M
83adnm
public class TestMethod { +SB>>
:R-_EY$k6
%/4_|.8u
public TestMethod() ]vflx^<?
{ ///xx/weblogic60b2_win.exe xZ]QT3U+
try{ +n%d,Pz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @DNwzdP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y#5v5
SiteFileFetch fileFetch = new SiteFileFetch(bean); J2Mq1*Vpq
fileFetch.start(); {E;oirv&
} Nz77" kC
catch(Exception e){e.printStackTrace ();} dq{+-XaEk
Kqz+:E8D
@<jm+f"MP
} !(F?Np Am
9Tg k=
l;SXR <EU
public static void main(String[] args) 6U0BP
{ A+MG?k>yg
new TestMethod(); WM;5/;bB
} >B<#,G
} b['v0x
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