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)); VWR6/,N^_
} ZAcW@xfb
for(int i=0;i<nEndPos.length-1;i++) "~zQN(sR"P
{ (#;<iu}
nEndPos = nStartPos[i+1]; V$XCe
} 8g CQ0w<
nEndPos[nEndPos.length-1] = nFileLength; [>tyx{T Ye
} XT 'v7
} \%D/]"@r
XN1\!CM8
DsP FBq
//启动子线程 g` QbJ61a
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H6PS7g"
for(int i=0;i<nStartPos.length;i++) Pq:GvM`
{ qhiO( !jK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m!-,K8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), GGR hM1II
nStartPos,nEndPos,i); g[~"c}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gM<*(=x'
fileSplitterFetch.start(); T]tG,W1>i
} $zvqjT:>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S4?N_"m9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); !@x'?+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6mi:%)"
nEndPos = " + nFileLength); BiUOjQC#
// fileSplitterFetch[nPos.length-1].start(); aI6fPQe
AW+q#Is
SH/KC
//等待子线程结束 MH>CCT
//int count = 0; *MEDV1l_T
//是否结束while循环 )`ZTu -|
boolean breakWhile = false; .WR+)^&zz
;(0E#hGN
<d\Lvo[
while(!bStop) 8W|qm;J98
{ t(|\3$z
write_nPos(); BQol>VRu
Utility.sleep(500); m};Qng]
breakWhile = true; P%6-W5<
5mD]uB9
od7 [h5r
for(int i=0;i<nStartPos.length;i++) x*A_1_A
{ /OpVr15
if(!fileSplitterFetch.bDownOver) S;vE%
{ {/x["2a1
breakWhile = false; fBptjt_
break; qd9CKd
} }?pY~f
} (bIg6_U7\
if(breakWhile) 'Lw4jq
break; (1r.AG`g
D|u! KH
F]hKi`@
//count++; 2[W1EQI
//if(count>4) 38wt=0br
// siteStop(); qFo'"z`84
} cC_L4
mr+J#
y;+5cn C
System.err.println("文件下载结束！"); (LW4z8e#
} b5hJaXJN
catch(Exception e){e.printStackTrace ();} %E95R8SL
} &95iGL28Q
Zc"Vf]:
}*{@-v|_R
//获得文件长度 V[R33NYG
public long getFileSize() '1lr "}"Q+
{ &j\<UPn
int nFileLength = -1; h)EHaaf
try{ |fMjg'%{}
URL url = new URL(siteInfoBean.getSSiteURL()); !%' 1x2?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Th&* d;
httpConnection.setRequestProperty("User-Agent","NetFox"); lF]cUp#<
o#KGENd
_c=[P@
int responseCode=httpConnection.getResponseCode(); "T/ vE
if(responseCode>=400) 4WV'\R+m
{ D"WqJcDt
processErrorCode(responseCode); _~aFzM
return -2; //-2 represent access is error mC P*v-
} ;\@co5.=
3:Aw.-,i\
=&QC&CqEi
String sHeader; rO]7g
`C~RA,M
,EyZ2`|
for(int i=1;;i++) EP.nVvuL
{ \ltA&}!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); =HT:p:S
//Utility.log(in.readLine()); OI3UC=G
sHeader=httpConnection.getHeaderFieldKey(i); adG=L9 "n
if(sHeader!=null) bT|NZ!V
{ Tu Q@b
if(sHeader.equals("Content-Length")) ].f28bY
{ XeD9RMT
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Mp=2}d%P
break; Oj<.3U[C
} wYtL1D(
} <qD/ #$
else VeixwGZ.
break; 0MK|spc
} x0^O?UR
} =`f6@4H
catch(IOException e){e.printStackTrace ();} s;'XX}Y
catch(Exception e){e.printStackTrace ();} ^h+,Kn0@
6"^Yn.
yc.Vm[!
Utility.log(nFileLength); BJI}gm2y
x{Y}1+Y4
acuch
return nFileLength; e0O2>w
} M_tY:v
SFrQPdX6V
ncg5%(2
//保存下载信息（文件指针位置） e)dPv:oK3
private void write_nPos() 6QsH?!bu
{ 1JIL6w_
try{ H`/QhE
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0HUSN_3F
output.writeInt(nStartPos.length); 4`F(RweGx
for(int i=0;i<nStartPos.length;i++) fY@Y$S`Fh
{ ]M AB
// output.writeLong(nPos); BKDs3?&
output.writeLong(fileSplitterFetch.nStartPos); *"V5j#F_
output.writeLong(fileSplitterFetch.nEndPos); {6%vmMbJ
} t0_o.S
output.close(); %4#,y(dO
} >jEn>H?
catch(IOException e){e.printStackTrace ();} (4_7ICFI
catch(Exception e){e.printStackTrace ();} zx"'WM*
} #:0dqD=
F&US-ce:M
Bw-<xwD
//读取保存的下载信息（文件指针位置） =[%ge{,t
private void read_nPos() sBP.P7u
{ s(56aE
try{ pEk^;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~ZeF5
int nCount = input.readInt(); SH>L3@Za
nStartPos = new long[nCount]; E"!I[
nEndPos = new long[nCount]; K*;e>{p
for(int i=0;i<nStartPos.length;i++) `>CHE'_
{ fE"Q:K6r2
nStartPos = input.readLong(); T^LpoN/T
nEndPos = input.readLong(); ~l$u~:4Ob
} ,KvF:xqA
input.close(); cIqk=_]
} g_lj/u]P
catch(IOException e){e.printStackTrace ();} hwF9LD~^
catch(Exception e){e.printStackTrace ();} 6<sd6SM
} 9(?9yFbj5
f49pIcAq
X._skq
private void processErrorCode(int nErrorCode) v"M5';ZS>
{ D<}z7W-
System.err.println("Error Code : " + nErrorCode); );T0n
} _ndc^OG
<a/TDW
4yhan/zA
//停止文件下载 i#/,Q1yEn
public void siteStop() gycjIy@t
{ Rh!B4oB4
bStop = true; dQUZ11
for(int i=0;i<nStartPos.length;i++) ^mWOQ*zi;
fileSplitterFetch.splitterStop(); v~|~&Dwq
\)Sa!XLfT
N{L'Q0!
} !u@XEN>/
} @tQu3Rq@
//负责部分文件的抓取 N$1ZA)M
**FileSplitterFetch.java [ kI|Thx
*/ u{#}Lo>B #
package NetFox; y/}[S@4uB
E`#m0Q(8
*|)a@VL
import java.io.*; yW::`
import java.net.*; 32yGIRV
~)5NX 4Po
8MIn~
public class FileSplitterFetch extends Thread { uTsxSkHb/
'@4Myg* b
~s.~X5
String sURL; //File URL +NML>g#F~z
long nStartPos; //File Snippet Start Position gc~nT/lfK
long nEndPos; //File Snippet End Position bf1Tky=/
int nThreadID; //Thread's ID X.~z:W+
boolean bDownOver = false; //Downing is over Ziclw)
boolean bStop = false; //Stop identical F@m]Imn5Dx
FileAccessI fileAccessI = null; //File Access interface ?HD(EGdx
?`9XFE~a!
~Mk{2;x
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L`sg60z
{ Hzm<KQ g
this.sURL = sURL; E?\&OeAkO
this.nStartPos = nStart; @9,=|kxK
this.nEndPos = nEnd; QaAA@l
nThreadID = id; 'gBns
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ^\<nOzU?
} --S1p0
.h({P#QT
}~W:3A{7;
public void run() k2bjBAT
{ U}#3LFr.?
while(nStartPos < nEndPos && !bStop) _H{6{!=y
{ 0.pZlv
1omjP`]|,
kSW=DE|#}
try{ MP/@Mf\<E
URL url = new URL(sURL); &Hz{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %@L[=\ 9
httpConnection.setRequestProperty("User-Agent","NetFox"); o7gYj\
String sProperty = "bytes="+nStartPos+"-"; {oXU)9vj
httpConnection.setRequestProperty("RANGE",sProperty); 9Wu c1#
Utility.log(sProperty); BE0Ov{'
% w\
s=S9y7i(R
InputStream input = httpConnection.getInputStream(); EF>vu+YK
//logResponseHead(httpConnection); wDQ@$T^vh
I45 kPfu
5taR[ukM
byte[] b = new byte[1024]; [c^!;YBp)
int nRead; G_m$?0\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) kC,=E9)O
{ v9,<2
nStartPos += fileAccessI.write(b,0,nRead); us5<18M5
//if(nThreadID == 1) }}Zwdpo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -/V,<@@T
} kk`K)PESi
Gye84C2E=
X!b+Dk
Utility.log("Thread " + nThreadID + " is over!"); cp:U@Nh(
bDownOver = true; P,Z K
//nPos = fileAccessI.write (b,0,nRead); %nS(>X<B
} Z5j\ M
catch(Exception e){e.printStackTrace ();} =:M/hM)#
} ybC0Ee@
} +P &S0/
1^ijKn@6
&lCOhP#
//打印回应的头信息 D_N0j{E
public void logResponseHead(HttpURLConnection con) 8aqH;|fG}
{ .9u0WP95
for(int i=1;;i++) :@RX}rKG
{ \y(ZeNs
String header=con.getHeaderFieldKey(i); %A3ci[$g
if(header!=null) B:>>D/O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qyKI.X3n*
Utility.log(header+" : "+con.getHeaderField(header)); <Fi*wV
else Gw$Y`]ipy
break; Q\nIU7:bZ
} /HE{8b7n3F
} SIZ&0V
j0b>n#e7
x MFo
public void splitterStop() R0#'t+7^
{ o(gV;>I
bStop = true; Rb_%vOM
} p[K!.vOt+
JLbmh1'
>g;995tG
} UL.YDU)
b&*)C#7/T
kXgc'w6EhF
/* nh]HEG0CZJ
**FileAccess.java `J$7X
*//文件访问(定位，写) +,_%9v?3
package NetFox; <c&Nm_)
import java.io.*; Hva/C{Y
c 'rn8Jo}
1=_Qj}!1
public class FileAccessI implements Serializable{ ]P96-x
[7\x(W-:@>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 xC9?Wt'
RandomAccessFile oSavedFile; U/A [al
long nPos; r3+
3$9V4v@2
C;%1XFzM
public FileAccessI() throws IOException X.V4YmZ-;
{ UZ1Au;(|
this("",0); RgVnx]IF
} h!7Lvh`o
.;)V;!
SPp|/ [i7
public FileAccessI(String sName,long nPos) throws IOException Fd#Zu.Np
{ ?ph>:M
oSavedFile = new RandomAccessFile(sName,"rw"); <cFj-Ys(T
this.nPos = nPos; 8H,k0~D
oSavedFile.seek(nPos); ]QQeUxi
} |_hIl(6F5N
yG^pND>_df
PU4-}!K
public synchronized int write(byte[] b,int nStart,int nLen) J(SGaHm@
{ Z^J7r&\V
int n = -1; BDCyeC,Q3
try{ z 'V$)U$f
oSavedFile.write(b,nStart,nLen); rN,T}M=2
n = nLen; n7|,b- <
} O"#/>hmv-
catch(IOException e) Ed+jSO0
{ SX&Q5:
e.printStackTrace (); T!i$nI&
} Hzz v 6k
. I."q
i v.G
return n; L4ZB0PmN'
} S%e)br}
,b:~Vpb1I
&}t8O?!
} D^}2ilk!
$Tal.
ay#f\P!1
/* biS{.
**SiteInfoBean.java ]0g p.R
*/ l&5Tft
package NetFox; o$Y#C{wC%
>hzSd@J&
}Syd*%BR[
public class SiteInfoBean { j<R&?*
57q?:M=^
FNw]DJ]
private String sSiteURL; //Site's URL 2XEE/]^
private String sFilePath; //Saved File's Path 13*S<\
private String sFileName; //Saved File's Name P#V}l'j(<a
private int nSplitter; //Count of Splited Downloading File xo2jfz
QKhGEW~G
ah,"c9YX
public SiteInfoBean() ]u:_r)T
{//nSplitter的缺省值为5 xu{VU^'Y
//default value of nSplitter is 5 /x4L,UJ= P
this("","","",5); m/;fY>}3
} Xoha.6$l5
9m\Yi
bR;.KC3C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ZAn9A>5_
{ NNwGRoDco
sSiteURL= sURL; Vol}wc
sFilePath = sPath; &C)97E
sFileName = sName; -8R SE4)
this.nSplitter = nSpiltter; ?b"'w
FsQoQ#*
t<j_` %`8
} \;!7IIe#
fn.;C
fJ6Q:7
public String getSSiteURL() eKo=g|D
{ f0R+Mz8{
return sSiteURL; 7#Uzz"^
} ZE= Yn~XM
\Lg4Cx
9MQjSNYzo
public void setSSiteURL(String value) O1wo KkfV
{ &pR 8sySu
sSiteURL = value; UoUQ6Ij
} L"NfOST3'R
8TK*VOf`
0c8_&
public String getSFilePath() W$`#X
{ )]4=anJu@|
return sFilePath; kbJ4CF}H
} bTZ.y.sI
^FVmP d*1
k*!iUz{]
public void setSFilePath(String value) Rha|Rk~
{ -yTIv*y
sFilePath = value; |`s:&<W+kp
} da_0{;wR
]0[ot$Da6
2-Wy@\
public String getSFileName() FC||6vJth
{ ;*ULrX4[
return sFileName; *"4l}&
} Z",2db
H SGz-
tmM; Z(9t
public void setSFileName(String value) OdNcuiLa
{ JAI.NKB3
sFileName = value; D*?LcxX
} c@)?V>oe
w`3.wALb
8xG"hJR
public int getNSplitter() !(viXV5
{ |JP'j1 Ka
return nSplitter; ;sqxFF@
} v-^tj}jA
<h}x7y?
V<;_wO^
public void setNSplitter(int nCount) %6m' |(-
{ Uj3HAu
nSplitter = nCount; F- u"zox
} Y6v#0pT
} ;ceg:-Zqo
gjzWW0C
:nc%:z=O
/* Y6d~hLC
**Utility.java gs0`nysM#
*/ 3Co1bY:
package NetFox; D ] n|d+
csxn"Dz\
H\N}0^ea
public class Utility { aNQ(xiskb
TXS`ey
D%c^j9' 1
public Utility() lA;^c)
{ 'zT7$ .L
w'VuC82SZ
#o9CC)q5G
} OL:hNbw'~T
?i\V^3S n$
//线程睡眠 ko'V8r`V
public static void sleep(int nSecond) ZrA*MN
{ G\,B*$3
try{ ,# .12Q!
Thread.sleep(nSecond); <w8H[y"c
} 8x7TK2r
catch(Exception e) _5O~]}
{ QMrH%Y
e.printStackTrace (); X}C8!LA
} O:RN4/17
} ~|ZAS]
$AMcU5^b7
//日志 nGc'xQy0
public static void log(String sMsg) 6"}F KRR
{ a>,_o(]cW
System.err.println(sMsg); t7xJ"
} B4+u/hkbh?
uk,9N
k]RQ 7e
public static void log(int sMsg) vk(I7
{ !bnnUCTb\
System.err.println(sMsg); FYefn3b
} qf<o"B|_9
} V$Oj@vI
lb=fS%
>qO l1]uF
/* sE|8a
**TestMethod.java `022gHYv
*/ (dO0`wfM
package NetFox; p<l+js(5|
I|c?*~7*
~Hj c?*
public class TestMethod { 9:Bn-3)
K>XZrt
{BaPK&x,
public TestMethod() <veypLi"R
{ ///xx/weblogic60b2_win.exe T<yfpUzX
try{ ,lFzL3'_0x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dWwb}r(ky
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6!*zgA5M'
SiteFileFetch fileFetch = new SiteFileFetch(bean); \RFA?PuY
fileFetch.start(); ?G]yU
} <+b~E,
catch(Exception e){e.printStackTrace ();} Tgi7RAY
N#R8ez`
Ip8:~Fl]
} '9<8<d7?
dI=&gz
[kgCB7.V
public static void main(String[] args) Olt;^>MQ
{ ,,)'YhG(
new TestMethod(); [W<j
} Jiru~Vo+
} uLI;_,/:
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