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)); !A8^Xmz"
} :PbDU$x
for(int i=0;i<nEndPos.length-1;i++) J` {6l
{ q^rl)
nEndPos = nStartPos[i+1]; wxLXh6|6%_
} !~<siy
nEndPos[nEndPos.length-1] = nFileLength; I>h<b_y
} _nT{g
} 64Gi8|P
`P+(&taT
=j0x.fSe
//启动子线程 !/K8xD$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >zY \Llv
for(int i=0;i<nStartPos.length;i++) A CNfS9M_w
{ bAxTLIf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H'RL62!
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I.}1JJF*
nStartPos,nEndPos,i); !Q-wdzsp?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Iy {U'a!
fileSplitterFetch.start(); MWuXI1
} Ni[4OR$-O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]8U ~Iy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PX".Km p.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |pZo2F!.
nEndPos = " + nFileLength); ?BCyJ
// fileSplitterFetch[nPos.length-1].start(); }\v^+scD
)&W|QH=AI
#_Ea[q7v
//等待子线程结束 o6j"OZcv
//int count = 0; h"QbA"
//是否结束while循环 %/0gWG
boolean breakWhile = false; ^6/j_G
67<CbQZoN3
DM7}&~
while(!bStop) snk$^
{ %u]6KrG18b
write_nPos(); % mn />
Utility.sleep(500); z<C[nR$N
breakWhile = true; *)VAaGUX>
}F{=#Kqn^
\3NS>v[1
for(int i=0;i<nStartPos.length;i++) F%6*Df;cSe
{ |paP<$
if(!fileSplitterFetch.bDownOver) %= u/3b:o
{ P!+v:'P5f
breakWhile = false; HY;oy(
break; p?myuNd[
} .K9l*-e[=
} <*@~n- R$
if(breakWhile) 4UCwT1
break; 0M!0JJy#*
cb+y9wA
r=csi
//count++; IhW7^(p\
//if(count>4) $v&C@l \
// siteStop(); s17)zi,?4
} u.A}&'H
*$O5.`]
9 m8KDB[N
System.err.println("文件下载结束！"); ]U#of O
} 29=ob("
catch(Exception e){e.printStackTrace ();} azFJ-0n@"
} 0:Bpvl5
4M%|N
8pEA3py
//获得文件长度 p"P+8"`
public long getFileSize() jOCV)V9}
{ a(~X
int nFileLength = -1; bj`GGxzOb
try{ #6a!OQj
URL url = new URL(siteInfoBean.getSSiteURL()); )@9Eq|jMC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2c]751
httpConnection.setRequestProperty("User-Agent","NetFox"); .RmFYV0,
f:46.)Wj<
yT:2*sZRc
int responseCode=httpConnection.getResponseCode(); HT/!+#W.
if(responseCode>=400) 48z%dBmTT*
{ 4IW fp&Q!
processErrorCode(responseCode); +UWv}|
return -2; //-2 represent access is error =?W7OV^BE
} K. B\F)K
khjdTq\\
/t`|3Mw
String sHeader; sCJ|U6Q-
8D>5(Dg-
iz^a Qx/
for(int i=1;;i++) -J=6)
{ r]-n,
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ae=JG8Ht~
//Utility.log(in.readLine()); hlreeXv
sHeader=httpConnection.getHeaderFieldKey(i); )n"0:"Ou
if(sHeader!=null) 2u-J+
{ .h4NG4FIF
if(sHeader.equals("Content-Length")) QDj%m%Xd
{ c|3oa"6T>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iOIq2&sV
break; 4<tbZP3/6)
} rRe^7xGe7
} s[a\m,
else G0m$bi=z
break; 4S*ifl
} <BT18u\
} Kn3Xn`P?
catch(IOException e){e.printStackTrace ();} R`$Y]@i&B
catch(Exception e){e.printStackTrace ();} CAx$A[f<
W%5))R$
s)E8}-v
Utility.log(nFileLength); tq,^!RSbZ
#/Ob_~-?j
oQpGa>6U&
return nFileLength; )?OdD7gd
} SFh<>J^ 0a
!YpH\wUyvP
8&HBR #
//保存下载信息（文件指针位置） ;F- mt(Y
private void write_nPos() IR]5,K^l
{ dh%O {t
try{ >Q<XyAH~
output = new DataOutputStream(new FileOutputStream(tmpFile)); BPkL3Ev1V
output.writeInt(nStartPos.length); -rYb{<;ST
for(int i=0;i<nStartPos.length;i++) L<oQKe7Q:
{ Z #
// output.writeLong(nPos); L|<j/bP
output.writeLong(fileSplitterFetch.nStartPos); b 1.S21
output.writeLong(fileSplitterFetch.nEndPos); L_9uwua.B~
} $DfK}CT
output.close(); x>mI$K(6M
} wQhuU
catch(IOException e){e.printStackTrace ();} lvODhoT
catch(Exception e){e.printStackTrace ();} /~s<@<1!X
} '\d ldg#P
BUwL?
0\"#Xa+}8
//读取保存的下载信息（文件指针位置） <uBRLe`)
private void read_nPos() huA?*fat
{ x6JV@wA&
try{ 2gklGDJD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z&n2JpLY7
int nCount = input.readInt(); ;X]B0KFe7
nStartPos = new long[nCount]; I)#8}[vK
nEndPos = new long[nCount]; rSt5@f?
for(int i=0;i<nStartPos.length;i++) 'hWA&Xx+
{ ` ;mQ"lO
nStartPos = input.readLong(); #hn
nEndPos = input.readLong(); R+ \%
} d0}(d Gl
input.close(); bh5P98s
} Wtw,YFT
catch(IOException e){e.printStackTrace ();} 6wu`;>
catch(Exception e){e.printStackTrace ();} >`&2]Wc)
} )N~ p4kp
j7:r8? G
\z2y?"\?
private void processErrorCode(int nErrorCode) I+twI&GS
{ LHx ")H?,
System.err.println("Error Code : " + nErrorCode); 2!}F+^8'P
} 3 eF c
@=AQr4&
'MX|=K!C
//停止文件下载 !%}n9vr!}\
public void siteStop() )M"NMUuU"
{ e<{d{
bStop = true; V,VL?J\
for(int i=0;i<nStartPos.length;i++) ?(R#
fileSplitterFetch.splitterStop(); &qPezyt
A0@,^|]
FXY>o>K%h
} 8<0P Ssx
} fnr8{sr.2Z
//负责部分文件的抓取 OESKLjFt
**FileSplitterFetch.java WY>$.e
*/ h#}w18l
package NetFox; "|J6*s
f^hJAZ
XP!m]\E&I
import java.io.*; {E(2.'d
import java.net.*; #r"|%nOfY
h4KMhr
2DsP "q79k
public class FileSplitterFetch extends Thread { ?5ZvvAi
&0[L2x}7
Opf)TAl{
String sURL; //File URL f4AN"rW
long nStartPos; //File Snippet Start Position w(`g)`
long nEndPos; //File Snippet End Position /d6Rdl`w
int nThreadID; //Thread's ID *XWu)>*o
boolean bDownOver = false; //Downing is over <X{w^ cT_Q
boolean bStop = false; //Stop identical KI#v<4C$P
FileAccessI fileAccessI = null; //File Access interface >Q(\vl@N=
5Hj/7~ =
@+zWLq!1pB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E(6P%(yt8
{ *)B \M>
this.sURL = sURL; xc@$z*w
this.nStartPos = nStart; d>I)_05t
this.nEndPos = nEnd; NTZ3Np`
nThreadID = id; kq(><T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F~E)w5?\O
} 1Zp/EYWa{
E <j=5|0t
6J JA"] `
public void run() S}h d,"I
{ 3 ;F
while(nStartPos < nEndPos && !bStop) F[O147&C
{ UE5,Ml~X
";&PtLe
YwY?tOxBe
try{ 0e#PN@
URL url = new URL(sURL); /@ g 8MUq7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eJ<P
httpConnection.setRequestProperty("User-Agent","NetFox"); 6rmx{Bt
String sProperty = "bytes="+nStartPos+"-"; ,vvfk=-
httpConnection.setRequestProperty("RANGE",sProperty); k0\a7$}F
Utility.log(sProperty); xWa[qCr
saZK+kD4I
q[P>s{"
InputStream input = httpConnection.getInputStream(); QaEiPn~
//logResponseHead(httpConnection); A0A|cJP
W[`ybGR<
(>u1O V
byte[] b = new byte[1024]; ND?"1/s
int nRead; E]&N'+T
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) %nq<nfDT
{ 2P'Vp7f6 Y
nStartPos += fileAccessI.write(b,0,nRead); :+QNN<
//if(nThreadID == 1) .j,xh )v"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fk?!0M6d
} X1}M_h%
<W3p!
7z, $
Utility.log("Thread " + nThreadID + " is over!"); OA9P"*
bDownOver = true; $U7/w?gc'
//nPos = fileAccessI.write (b,0,nRead); sVP\EF8PY
} gzVZPvTPE
catch(Exception e){e.printStackTrace ();} (O09HY:
} N GnE
} bvZD@F`2
Zp_j\B
RaTNA W)v>
//打印回应的头信息 /o6ido
public void logResponseHead(HttpURLConnection con) E>*b,^J7g
{ n2AoEbd
for(int i=1;;i++) @##}zku
{ 4mp)v*z
String header=con.getHeaderFieldKey(i); CpX[8>&osD
if(header!=null) {P?DkUO}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); O{byMV{Ou
Utility.log(header+" : "+con.getHeaderField(header)); ?uTuO
else &u[F)|
break; q0>9T
} `l?MmIJ
} e'G3\h}#
I;_T_m4.q
\j)c?1*$
public void splitterStop() $$4flfx
{ BIx*(
bStop = true; o8E<_rei
} hB\BFVUSn/
d72 yu3
O3slYd&V
} hr'?#K
Q2)5A&U\
XZ$g~r
/* Dqwd=$2%
**FileAccess.java '#j6ZC/?
*//文件访问(定位，写) KdHkX+-R
package NetFox; }>y~P~`S:
import java.io.*; a8[%-eW,
\?e2qu/ C
p*cyW l
public class FileAccessI implements Serializable{ UDJ#P9uy
Pk5\v0vkg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >yVrIko
RandomAccessFile oSavedFile; ^56D)A=
long nPos; 3#udzC
V5h_uGOD
e>!]_B1ad
public FileAccessI() throws IOException 5gx;Bp^_
{ *)\y52z
this("",0); 5$Kv%U
} .|L9}<
K|~!oQ
q(s0dkrj
public FileAccessI(String sName,long nPos) throws IOException {t0!N]'
{ C$at9=(E6
oSavedFile = new RandomAccessFile(sName,"rw"); wp~KrUlR
this.nPos = nPos; T72Z<h|<
oSavedFile.seek(nPos); Avljrds+7
} zKYN5|17
5>1c4u`x
F)'_,.?0
public synchronized int write(byte[] b,int nStart,int nLen) Bgsi$2hI
{ !VG ]~lc
int n = -1; xQ?$H?5B<
try{ qIzv|Nte
oSavedFile.write(b,nStart,nLen); u,72Mm>
n = nLen; r`)'Kd
} +\PLUOk
catch(IOException e) $'*{&/@
{ yQu/({D
e.printStackTrace (); 98zJ?NaD&
} UNrO$aX!1'
ph2 _P[S'
Vn/FW?d7
return n; 4uE/!dT
} 5?j#
Y3)*MqZlF
Lq@uwiq!
} Dg ~k"Ice
65+2+p
"x_G6JE4tv
/* _a?x)3\v
**SiteInfoBean.java G}WY0FC6
*/ %3HF_DNOY=
package NetFox; ] TZ/=Id
(h@~0S
*a(GG
public class SiteInfoBean { [Q8vS;.
<1~_nt~(*
[*ug:PG
private String sSiteURL; //Site's URL &,/-<y-S
private String sFilePath; //Saved File's Path 90<a'<\|
private String sFileName; //Saved File's Name Z y6kA\q
private int nSplitter; //Count of Splited Downloading File vsq |m5
f.vJJa
[-)BI|S:
public SiteInfoBean() iNL>TVUM
{//nSplitter的缺省值为5 -7I%^u
//default value of nSplitter is 5 UD2l!)rW
this("","","",5); _*t75e$-
} ZU7u>
g</Mk^CE
<@n3vO6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `,c~M
{ ub4(g~E
sSiteURL= sURL; e:QH3|'y
sFilePath = sPath; j2hp*C'^
sFileName = sName; |gGD3H
this.nSplitter = nSpiltter; Q'^$;X~-<
$D*Yhv!/
[XA:pj;rg'
} vcOw`oS
/5f=a
cdL0<J b,
public String getSSiteURL() |Yi_|']#
{ *>lXCx
return sSiteURL; `7 Nk;
} cm>+f^4?n
Qz<i{r-z
jq/CXYv
public void setSSiteURL(String value) JWxSN9.X
{ ae+*gkPv8
sSiteURL = value; J@q!N;eh|
} #\LYo{op/.
KM oDcAjH
# *7ImEN
public String getSFilePath() y(**F8>?xE
{ xUB{{8B:L
return sFilePath; bg*@N
} SXV f&8
=d JRBl
~y:?w(GD
public void setSFilePath(String value) G/_8xmsU
{ ]rO/IuB
sFilePath = value; VQ2B|v
} o~'UWU'#
~2XiKY;W?
9@ ^*\s
public String getSFileName() OL@' 1$/A
{ 2 3A)^j
return sFileName; S<++eu
} sFRQFX0XoY
RWGAxq`9f
6#2E {uy;R
public void setSFileName(String value) /8>we`4
{ P#2#i]-
sFileName = value; Rap_1o9#\
} Rdy-6
B,{Q[
[g lhru=+
public int getNSplitter() 3=^B &AB
{ v*@R U
return nSplitter; kE{-h'xADD
} >6z7.d
\r\wqz7
|+aD%'|
public void setNSplitter(int nCount) ]7%+SH,RdD
{ )m10IyUAY
nSplitter = nCount; '&iAPc4=
} ']>/$[!
} xbze{9n"
:h<QM$P<
ju/#V}N
/* "l-b(8n
**Utility.java T:w%RF[v9
*/ 5GWC
package NetFox; [mG:PTK3
' "o2;J)7
24d{ol)
public class Utility { @Yzb6@g"
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8G_KbS
public Utility() W&9X <c*
{ A!_yZ|)$T
20BU;D3
zWq&HBs
} ID$%4jl
,) 3Eog\-
//线程睡眠 0d #jiG
public static void sleep(int nSecond) EceD\}
{ A@ 4Oq
try{ Qr*7bE(a
Thread.sleep(nSecond); +bcJm
} ^$J.l+<hy
catch(Exception e) Ku]<$uo
{ 95BRZ!ts
e.printStackTrace (); xayd_RB9
} T2MXwd&l
} wO*x0$
b:6e2|xf?
//日志 Ve|=<7%%S
public static void log(String sMsg) ~&Y%yN^
{ JcI~8;Z@Z~
System.err.println(sMsg); Zl=IZ?F
} K}Rq<zW
iVf8M$!m
9':MD0P/M
public static void log(int sMsg) #~;:i
{ ;Qdw$NuW
System.err.println(sMsg); Te&5IB-
} ~#9(Q
} !l#n.Fx&3
6^hCW`jG
](sT,'
/* \={A%pA;@{
**TestMethod.java U jB5Xks
*/ d<afO?"
package NetFox; ynG@/S6)K
Mp`i@pm+
[[vbw)u
public class TestMethod { fk?(mxx"
!1ZrS
B-EDVMu
public TestMethod() Vi\kB%
{ ///xx/weblogic60b2_win.exe ./E<v
try{ u75(\<{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )+12r6W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f!+G1z}iA
SiteFileFetch fileFetch = new SiteFileFetch(bean); ]sV) '-
fileFetch.start(); CC{{@
} [[VB'Rs
catch(Exception e){e.printStackTrace ();} 6Bn%7ZBv
Tq!.M1{&
s_Gf7uC
} jL9to6 Hmr
|s*tRag
~YCZvJ
public static void main(String[] args) C(lGW,!
{ "}jv5j5
new TestMethod(); lc\f6J>HT
} nM6/c
} ;\)N7SJ
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