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)); pU9.#O
} 5RvE ),
for(int i=0;i<nEndPos.length-1;i++) Q5ff&CE
{ JOpH Z?
nEndPos = nStartPos[i+1]; (BFwE@1"
} ~;?<OOt|wG
nEndPos[nEndPos.length-1] = nFileLength; pmUf*u-
} YGC%j
} r<vy6
VP>*J`'H
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//启动子线程 a_+?#m
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `vMhrn
for(int i=0;i<nStartPos.length;i++) y+T[="W
{ 9@ YKx0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 04jvrde8-O
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yq49fEgc@U
nStartPos,nEndPos,i); 6F!B*lr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8 eK8-R$
fileSplitterFetch.start(); $&&E[JY
} 2mnAL#
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), FLs$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Gc"hU:m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [nZIV
nEndPos = " + nFileLength); -&sY*(:n_
// fileSplitterFetch[nPos.length-1].start(); |4g0@}nr+W
/W)A[jR
=qc+sMo
//等待子线程结束 JLnv O
//int count = 0; w8>h6x"
//是否结束while循环 ,5"(m?[m
boolean breakWhile = false; aUzCKX%>C
oWL_Hh%-f`
u1L^INo/
while(!bStop) H)i|?3Ip
{ "5Y6.$Cuf!
write_nPos(); iX6>u4~(
Utility.sleep(500); Vn4wk>b}$2
breakWhile = true; =V]0G,,\
r":anR( ;
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for(int i=0;i<nStartPos.length;i++) ^L5-2;s<U'
{ y0sce
if(!fileSplitterFetch.bDownOver) w+>+hq
{ Jr( =Y@Z'
breakWhile = false; 4[@YF@_=M
break; t|eH'"N%o
} E#!!tH`lgg
} _ Lb"yug
if(breakWhile) fE+zA)KX
break; 7n6g;8xE
z,G_&5|f%
hp)^s7H
//count++; gr SF}y!3
//if(count>4) GM0Q@`d
// siteStop(); H:]cBk^[,
} {?eUAB<
<kdlXS>J.
NDP" @
System.err.println("文件下载结束！"); [p9v#\G; [
} W\k8f+Ke
catch(Exception e){e.printStackTrace ();} ?:J_+?{E
} H#_Zv]
HKXC=^}x'
+q}t%K5
//获得文件长度 <;S$4tux
public long getFileSize() ![^pAEgx
{ YND}P9 h
int nFileLength = -1; bsF_.S*k@
try{ bu|.Jw"
URL url = new URL(siteInfoBean.getSSiteURL()); lb.Q^TghU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6sSwSS
httpConnection.setRequestProperty("User-Agent","NetFox"); Y@0'0
SOhM6/ID2/
e4YP$}_L
int responseCode=httpConnection.getResponseCode(); )&c#?wx'w
if(responseCode>=400) nf0u:M"fm
{ IibrZ/n6
processErrorCode(responseCode); :.,9}\LK
return -2; //-2 represent access is error ]alc%(=
} & "&s,
\~l_w ,Poo
`SFeln{1B
String sHeader; @|SeabN^-
t\K (zE
ZpVkgX4
for(int i=1;;i++) rk W7;!
{ 5,1<A@H
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0cq@lT6
//Utility.log(in.readLine()); -!Myw&*\V
sHeader=httpConnection.getHeaderFieldKey(i); A/>Q5)
if(sHeader!=null) a)JXxst
{ g[O?wH-a
if(sHeader.equals("Content-Length")) ;Zd_2CZ
{ N $) G8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); #m.e9MU
break; v 49o$s4J
} F'Y ad
} cRVL1ne
else C7FQc{
break; y4Jc|)
} Cy]=Y
} WFOJg&
catch(IOException e){e.printStackTrace ();} HeAXZA,
catch(Exception e){e.printStackTrace ();} Io]FDPN
V.P<>~W
ZwS:Te9-
Utility.log(nFileLength); ma~#E$i&
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a/j;1xcc<
return nFileLength; -`~qmRpqY
} Cg): Q8
A)&FcMO*z
0N,<v7PX
//保存下载信息（文件指针位置） s1D<R,J|H
private void write_nPos() a:)FWdp?9
{ R ZY=c
try{ OOqT0wN
output = new DataOutputStream(new FileOutputStream(tmpFile)); il5C9ql$
output.writeInt(nStartPos.length); JXK\mah
for(int i=0;i<nStartPos.length;i++) X&pYLm72;
{ #{8IFA
// output.writeLong(nPos); \X8b!41
output.writeLong(fileSplitterFetch.nStartPos); *y*tI}
output.writeLong(fileSplitterFetch.nEndPos); zFq%[X
} !4vb{AH
output.close(); fHup&|.
} 4!/JN J
catch(IOException e){e.printStackTrace ();} /| v.A\:
catch(Exception e){e.printStackTrace ();} <kK>C8+
} 7AV{ h[J
KNx/1lf
m^D'p
//读取保存的下载信息（文件指针位置） DXLXGvcM
private void read_nPos() xnY?<?J"!
{ $Z@*!B^
try{ ?G,4N<]Nu
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k&dXK
int nCount = input.readInt(); G]'ah1W
nStartPos = new long[nCount]; Hb=#`
nEndPos = new long[nCount]; jSY[Y:6md
for(int i=0;i<nStartPos.length;i++) VsQ|t/|#
{ qVn<c,8#
nStartPos = input.readLong(); nje7?Vz
nEndPos = input.readLong(); ENTcTrTn
} aOzIo-
input.close(); V.GM$
} !=dz^f.{
catch(IOException e){e.printStackTrace ();} 1B~O!']N<
catch(Exception e){e.printStackTrace ();} >v:ex(y0
} ra$:ibLN
FU3K?A B
.k,j64 r
private void processErrorCode(int nErrorCode) (C!p2f
{ V?u#WJy/
System.err.println("Error Code : " + nErrorCode); aA`eKy) \
} J2=4%#R!
$Ll9ak}
GcVQz[E
//停止文件下载 NIV}hf YF
public void siteStop() #fuUAbU0X
{ z#tIa
bStop = true; iq; | i!
for(int i=0;i<nStartPos.length;i++) C*Vm}|)
fileSplitterFetch.splitterStop(); {D4FYr J
{*yvvb
0JlNUO5Nt
} 9-42A7g^C
} F9r.DG$}
//负责部分文件的抓取 &6x(%o|
**FileSplitterFetch.java g*V.u]U!i
*/ (T%F^s5D
package NetFox; 1q}LO2
V:n0BlZ,B
OIblBQ!
import java.io.*; Lw>B:3e
import java.net.*; PtfG~$h?
$Rm~ VwY#
UQl?_[G
public class FileSplitterFetch extends Thread { @Q74
*S;}&VAZ
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String sURL; //File URL N<)CG,/w[M
long nStartPos; //File Snippet Start Position @>8(f#S%
long nEndPos; //File Snippet End Position 7Nq< o5
int nThreadID; //Thread's ID >tM4|w|
boolean bDownOver = false; //Downing is over @;/Pl>$|'G
boolean bStop = false; //Stop identical \"O5li3n
FileAccessI fileAccessI = null; //File Access interface X=sE1RB
>XgoN\w
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException b'z $S+
{ C>Ik ;
this.sURL = sURL; 7hk)I`o65
this.nStartPos = nStart; c^r8<KlI9
this.nEndPos = nEnd; z$1RD)TQB
nThreadID = id; a~_9BM41T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8+'}`
} [DaAvN^0A
Q0J1"*P0
^#_gk uyd!
public void run() m%|\AZBA#
{ HWjJ.;k}a
while(nStartPos < nEndPos && !bStop) ^z *0
{ uKJ:)oyaCP
4$Ai!a
q<09]i
try{ SyL"Bmi
URL url = new URL(sURL); DGTLlBkT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); # &v4c
httpConnection.setRequestProperty("User-Agent","NetFox"); c9|4[_&B~
String sProperty = "bytes="+nStartPos+"-"; )M8d\]
httpConnection.setRequestProperty("RANGE",sProperty); [c?0Q3F
Utility.log(sProperty); ;As~TGiT
\RDN_Z
u3h(EAH>
InputStream input = httpConnection.getInputStream(); ('z=/"(l
//logResponseHead(httpConnection); 5U?O1}P
$JFjR@j
2Io|?
byte[] b = new byte[1024]; rc=E%Qv%?
int nRead; 392V\qtS
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (PpY*jKR
{ x?Sx cQP
nStartPos += fileAccessI.write(b,0,nRead); 7'wpPXdY1
//if(nThreadID == 1) ?'V78N sA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <exCK*G
} voZaJ2ho/O
k=)U
IogLkhWX
Utility.log("Thread " + nThreadID + " is over!"); C >OeULD
bDownOver = true; Hca(2 ]T-
//nPos = fileAccessI.write (b,0,nRead); !{&r|6
} uI,*&bP
catch(Exception e){e.printStackTrace ();} ZcA"HD%
} :V9Q<B^
} N<JI^%HBgP
UN?tn}`!
TXB!Y!RG#
//打印回应的头信息 Z_ElLY
public void logResponseHead(HttpURLConnection con) \%r#>8c8
{ r'i99~
for(int i=1;;i++) Rxy|Ag/I;V
{ &OU.BR>
String header=con.getHeaderFieldKey(i); rVabkwYD
if(header!=null) M>k&WtqK
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S1r{2s&
Utility.log(header+" : "+con.getHeaderField(header)); '&CZ%&(Gw
else 0hS&4nW
break; N<#J!0w
} k7Nx#%xx
} oypLE=H
u8"s#%>Ny
|1wZ`wGZ:L
public void splitterStop() H [+'>Id:
{ @;EQ{d
bStop = true; i?_Q@uA~<:
} mLq0;uGL|
P~(&lu/;P
:$Cm]RZ
} !KV!Tkx h
" lD -*e4
l"8g9z
/* 88u[s@
**FileAccess.java thPAD+u.3
*//文件访问(定位，写) %Vo'\|
package NetFox; $Y/z+ea
import java.io.*; 2K~v`c*4
{:cGt2*~^
ceg\lE:8
public class FileAccessI implements Serializable{ 5]{rim
!jP[=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /8Lb_QH{
RandomAccessFile oSavedFile; !UzE&CirV
long nPos; ,vR>hyM
}ll&EB
ccv
public FileAccessI() throws IOException 0Cc3NNdz
{ *r>Y]VG;S
this("",0); 1drg5
} K`=U5vG^
xgOt%7sb
K81FKV.
public FileAccessI(String sName,long nPos) throws IOException ~&/Nl_#
{ K%9!1'
oSavedFile = new RandomAccessFile(sName,"rw"); =YM
this.nPos = nPos; qLBQ!>lR
oSavedFile.seek(nPos); UXSwd#I&
} Ez <YD
kU:Q&[/jzH
jhT/}"v
public synchronized int write(byte[] b,int nStart,int nLen) i@{b+5$
{ Tu:lIy~A
int n = -1; ruhC:rg:/
try{ Fkv284,LM
oSavedFile.write(b,nStart,nLen); W&A^.% 2l
n = nLen; +fvVora
} HmXxM:[4;
catch(IOException e) pDC`Fi
{ i{g~u<DH)Q
e.printStackTrace (); yJx,4be
} %5ov!nm7
} %3;j5 ;6
9'X"a
return n; g9GPyU
} =j_4!^
!rx5i
nJH'^rO!C
} ;&b=>kPlZ
m%U=:u7#M
.:-*89c
/* i39_( )X
**SiteInfoBean.java uxW |&q
*/ %i&am=
package NetFox; MDpx@.A,
][f0ZMa
J^kSp
public class SiteInfoBean { -6q7ze{@
BT:b&"AR[
_J>Ik2EF
private String sSiteURL; //Site's URL :>y5'q@R
private String sFilePath; //Saved File's Path dn5t7D^x
private String sFileName; //Saved File's Name ~LH).\V
private int nSplitter; //Count of Splited Downloading File @&h_+|:-
Q{hK+z`D
&Ai+t2
public SiteInfoBean() $9@Z\0
{//nSplitter的缺省值为5 ?:PF;\U
//default value of nSplitter is 5 %AMF6l[
this("","","",5); _=w=!U&W
} d.snD)X
a/d8_(0
nQw, /Lk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ylmVmHmc
{ * se),CP!s
sSiteURL= sURL; UuJ gB)
sFilePath = sPath; Dhft[mvo
sFileName = sName; 2J(,Xf
this.nSplitter = nSpiltter; m7,"M~\pX
m,J9:S<5;
FOa2VP%
} \a:-xwUu<
Dk~ JH9#
`C:J{`
public String getSSiteURL() )q7!CG'oY
{ N8wA">u
return sSiteURL; !&8B8jHqA
} !;PKx]/&
K`R
=rNI&K_<
public void setSSiteURL(String value) S?H qrf7<
{ Yu9(qRK
sSiteURL = value; e58tf3
} $+ \JT/eG9
;;17 #T2
%Y].i/".;P
public String getSFilePath() =sXk,I;
{ e=6C0fr
return sFilePath; uQkFFWS
} 0Q/BTT%X
S#D6mg$Z,
g<4@5OQKu
public void setSFilePath(String value) %?`$#*f\%
{ i;<H^\%
sFilePath = value; Ut"F b
} :jWQev"/
6$+F5T
NSh~O!pX
public String getSFileName() tjy@sO/Q
{ &C E){jC
return sFileName; $Jy1=/W&
} E7Pz~6
]\%u9,b%!
BG20R=p
public void setSFileName(String value) s4\_%je<v
{ \N]2V(v
sFileName = value; wtro'r3
} 4q^'MZm1
[tz}H&
#F >R5 D
public int getNSplitter() mvW,nM1Y
{ , rc %#eF
return nSplitter; NHzhGg]
} IsiCHtY9
X[iQ%Y$/n
Rp""&0
public void setNSplitter(int nCount) ~d6zpQf7>
{ y[:xGf]8@
nSplitter = nCount; #ruL+-8!<
} /4-6V d"8
} arj?U=zy
)1!*N)$
1O;q|p'9
/* |lf,3/*jDB
**Utility.java g)~"-uQQ
*/ K@@[N17/8
package NetFox; fnO>v/&B
~Wj. 4b*
sq'bo8r
public class Utility { w97%5[-T
2~*.X^dR
eB*0})
public Utility() 8d"Ff
{ 0h~7"qUF@
3,-xk!W$L
2_Otv2
} <-m[0zgq
.qk_m-o
//线程睡眠 qUtlh,4)
public static void sleep(int nSecond) 7^Q4?(A
{ c'~6 1HA<
try{ UB1/0o
Thread.sleep(nSecond); Vq<\ixRi
} ?Q%X,!~\:
catch(Exception e) 0T7""^'&
{ gCY%@?YyN
e.printStackTrace (); ify}xv
} Mu]1e5^]
} `Kq4z62V
i"o %Gc
//日志 +(3U_]Lu
public static void log(String sMsg) K.K=\ Y2
{ uMe]].04
System.err.println(sMsg); i_6 Y6
} o&"nF+,
aoVfvz2Y
?#P@N4Uw}y
public static void log(int sMsg) {]6Pd`-
{ _B5v&#h(.
System.err.println(sMsg); `z{sDe;
} m_g2Cep
} 3=~0m
8%D 2G i
{:0TiOP5x
/* NvqIYW
**TestMethod.java \_J;i[
*/ a8laPN
package NetFox; 1z$K54Mj
;HbAk`\1A
^6(Nu|6\@
public class TestMethod { @is!VzE
TO~Z6NA0
>")<pUQ
public TestMethod() Q,m1mIf
{ ///xx/weblogic60b2_win.exe U^.kp#x#
try{ 6<h ==I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dGY:?mf&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !O}^Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); a08`h.dyN
fileFetch.start(); /I/gbmc)
} I c 2R\}q
catch(Exception e){e.printStackTrace ();} Z0I>PBL@l
;Wu6f"+Y#
8\{1y:|
} _gl7Ma
^\ocH|D
JcDcYB
public static void main(String[] args) 1Vy8TV3D
{ \DC0`
new TestMethod(); osdl dS
} :7[20n}w
} q71~Y:7f
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