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)); $i+@vbU6
} b}NNkM
for(int i=0;i<nEndPos.length-1;i++) NUVKAAgMX
{ $)NS]wJ]3
nEndPos = nStartPos[i+1]; ~.3v\Q
} mhrF9&s
nEndPos[nEndPos.length-1] = nFileLength; s.7=!JQ#]p
} %`k [xz
} 9NwUXh(:(
`l'T/F\
`PAQv+EYz
//启动子线程 |HT7m5tu4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QBXEM=
for(int i=0;i<nStartPos.length;i++) m2^vH+wD
{ s?;8h &]=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9soEHG=P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *7H *epUa
nStartPos,nEndPos,i); roc DO8f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >m lQ@Z_O
fileSplitterFetch.start(); 'dBe,@
} {Ni]S$7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ojz'p5d`>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3m75mny
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", vrb@::sy0T
nEndPos = " + nFileLength); v\|jkzR5Y
// fileSplitterFetch[nPos.length-1].start(); `w#VYs|k
TO89;O
\{ | GK
//等待子线程结束 0<v5_pB
//int count = 0; PP$2s]{
//是否结束while循环 AP%R*0]
boolean breakWhile = false; +&)/dHbL`]
#z>I =gl
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while(!bStop) *K_8=TIA*
{ 0IqGy}+VU
write_nPos(); d6*84'|!
Utility.sleep(500); mW!n%f
breakWhile = true; <eMqg u
V-#JV@b
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for(int i=0;i<nStartPos.length;i++) rfVQX<95=/
{ |dEPy-Xe
if(!fileSplitterFetch.bDownOver) o_Z9\'u
{ ZqrS]i@$
breakWhile = false; ?" 4X&6xl
break; 8y6dT
} @"NP`#
} pLe4dz WA
if(breakWhile) D~ 3@v+d
break; MzUKp"
-4+'(3qr
4+>yL+sC%v
//count++; *cM=>3ws/
//if(count>4) uQH]
// siteStop(); 0J/yd
} V0{#q/q
+`wr{kB$~
UfPB-EFl$D
System.err.println("文件下载结束！"); k0=!%f_G!
} 0qNmao4E_
catch(Exception e){e.printStackTrace ();} wxcJ2T dH
} Wjq9f;
]Xa]a}[uE
LE{@J0r#n
//获得文件长度 Sak^J.~G[
public long getFileSize() ($`IHKF1.l
{ _Ycz@Jn
int nFileLength = -1; XdThl
try{ 7#+Ih-&EQ
URL url = new URL(siteInfoBean.getSSiteURL()); ~Yc~_)hD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M887 Q'HSi
httpConnection.setRequestProperty("User-Agent","NetFox"); k-3;3Mq
aNKw.S>
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int responseCode=httpConnection.getResponseCode(); *JX$5bZsI
if(responseCode>=400) ]\K?%z
{ &TRKd)wd
processErrorCode(responseCode); 0 N7I:vJ
return -2; //-2 represent access is error 9;XbyA]
} MVzj7~+
gYN;Fu-9Z
XGR63hXND
String sHeader; XM!oN^
"Cxj_V@\
i7T#WfF
for(int i=1;;i++) }2S!;swg+
{ 6!0NFP~b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <<S4l~"o
//Utility.log(in.readLine()); cd,'37pZ
sHeader=httpConnection.getHeaderFieldKey(i); cHr]{@7Cs
if(sHeader!=null) ='D%c^;O8'
{ bE% Hm!
if(sHeader.equals("Content-Length")) /Z*$k{qIR&
{ L|APXy]>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); p&Nav,9x
break; +&"W:Le:
} &u|t{C#0
} =.S2gO >
else %LC)sSq{H
break; 4N=,9
} U7fpaxc-
} hb~d4J=S
catch(IOException e){e.printStackTrace ();} =CFg~8W
catch(Exception e){e.printStackTrace ();} 2&'uO'K
jo"+_)]
jN{k }
Utility.log(nFileLength); +e>G V61
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bZWR.</
return nFileLength; YdvXp/P:|
} X)]>E]X
EhO\N\p(Q=
pHVDug3
//保存下载信息（文件指针位置） /oe0
private void write_nPos() W'k&DKhTqF
{ 5[zr(FuE
try{ !^L}LtqHI
output = new DataOutputStream(new FileOutputStream(tmpFile)); as3uz
output.writeInt(nStartPos.length); 9VaSCB
for(int i=0;i<nStartPos.length;i++) |:(BI5&S
{ k(>J?\iNW
// output.writeLong(nPos); PNLlJlYlP
output.writeLong(fileSplitterFetch.nStartPos); :.H@tBi*E
output.writeLong(fileSplitterFetch.nEndPos); YVRE9
} _`QMEr?
output.close(); jyg>'"W
} sdXchVC
catch(IOException e){e.printStackTrace ();} .w\4Th#
catch(Exception e){e.printStackTrace ();} a&[[@1OY
} &flcJ`
~O./A-l
PTpCiiA@
//读取保存的下载信息（文件指针位置） $aXYtHI
private void read_nPos() .ZQXY%g
{ 2mj>,kS?c
try{ |OF3J,q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bU}!bol
int nCount = input.readInt(); /Y\q&}
nStartPos = new long[nCount]; -{eiV0<^
nEndPos = new long[nCount]; 7je1vNs
for(int i=0;i<nStartPos.length;i++) /mE:2K]C
{ c?xeBC1-
nStartPos = input.readLong(); J=^5GfM)J
nEndPos = input.readLong(); ND9;%<80
} *sfz+8Y
input.close(); _jkJw2+s\
} v/KTEM
catch(IOException e){e.printStackTrace ();} Dh{P23}
catch(Exception e){e.printStackTrace ();} 5.0;xz}#y
} g+.E=Ef8<4
t?uw^nV3E
&U.y):
private void processErrorCode(int nErrorCode) c$A}mL_
{ e!i.u'z
System.err.println("Error Code : " + nErrorCode); ?1]B(V9nBq
} ,aWfGh#$
nYRD>S?uz
Pd 6
//停止文件下载 *=E4|>Ul,
public void siteStop() IfRrl/!nw
{ %ULd_ES^
bStop = true; "J >, Hr9
for(int i=0;i<nStartPos.length;i++) OK}8BY
fileSplitterFetch.splitterStop(); WFeaX7\b
U/(R_U>=
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} t.O4-+$ig
} /s:akLBaD
//负责部分文件的抓取 >273V+dy
**FileSplitterFetch.java Yu^}
*/ v g tJ+GjN
package NetFox; &zP\K~Nt
m} =<@b:l
+fIyeX
import java.io.*; JR_c]AQYu
import java.net.*; L?y,xA_
[7)#3
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public class FileSplitterFetch extends Thread { -gS/
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M[T!AO-S$
String sURL; //File URL p:U{3uN 62
long nStartPos; //File Snippet Start Position \}qv}hU
long nEndPos; //File Snippet End Position ]@1ncn7N
int nThreadID; //Thread's ID h"nv[0!)
boolean bDownOver = false; //Downing is over 0$nJd_gW_
boolean bStop = false; //Stop identical U`'w{~"D%
FileAccessI fileAccessI = null; //File Access interface :(x 90;DW
!C0= h
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException WUi7~Ei}
{ %}&9[#
this.sURL = sURL; z<P#djx
this.nStartPos = nStart; xhMdn3~U
this.nEndPos = nEnd; f.r-,%^6{
nThreadID = id; Y!s/uvRI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 V'?nS&,i
} WqU$cQD"
5O%}.}n
*m]%eU(
public void run() Z=sAR(n}~
{ {k~$\J?.
while(nStartPos < nEndPos && !bStop) 17qrBG-/MD
{ ]R]X#jm
')FNudsC
PwNLJj+%
try{ .g&BA15<F6
URL url = new URL(sURL); E3KPJ`=!*"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ,9M \`6
httpConnection.setRequestProperty("User-Agent","NetFox"); N4mQN90t
String sProperty = "bytes="+nStartPos+"-"; aH$*Ue@Q
httpConnection.setRequestProperty("RANGE",sProperty); DwTZ<H4
Utility.log(sProperty); +Q_Gm3^
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"ChBcxvxb:
InputStream input = httpConnection.getInputStream(); z?YGE iR/}
//logResponseHead(httpConnection); T +4!g|Y
i|d41u;@
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byte[] b = new byte[1024]; y.oJzU[p%
int nRead; MDCf(LhEH
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a+BA~|u^
{ Em.?
nStartPos += fileAccessI.write(b,0,nRead); `RzM)ILl
//if(nThreadID == 1) =XS'V*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wYawG$@_
} p9sxA|O=y
4-n.4j|
I5"=b}V5
Utility.log("Thread " + nThreadID + " is over!"); u})JQ<|
bDownOver = true; \)"qN^we
//nPos = fileAccessI.write (b,0,nRead); ?%0i,p@<
} QY fS-
catch(Exception e){e.printStackTrace ();} "7 4L
} ]V]o%onW
} XF$C)id2p
nW%c95E
BPOWo8TqD^
//打印回应的头信息 &]c9}Ic
public void logResponseHead(HttpURLConnection con) dCyQCA[
{ wb9zJAsc
for(int i=1;;i++) }w@nZG ^&
{ Y\x Xo?
String header=con.getHeaderFieldKey(i); Qqaf\$X
if(header!=null) J8D-a!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QBo^{],
Utility.log(header+" : "+con.getHeaderField(header)); tr}$82Po
else y@z#Jw<
break; ^b.J z}
} \5l}5<|
} TPzoU" qh
/kq~*s
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public void splitterStop() 5~? J
{ 0?sp
bStop = true; O#|E7;
} Q&LkST-i
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mnia>; 0H
} J{ Vl2P?@
#75;%a8
Mf63 59
/* tpctz~ .
**FileAccess.java *dl@)~i
*//文件访问(定位，写) ,O+7nByi[V
package NetFox; 1$W!<:uh
import java.io.*; ~}116K
KP(Bu0S
_Owz%
public class FileAccessI implements Serializable{ M@3H]t?
zYNJF>^<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U|QDV16f
RandomAccessFile oSavedFile; |g{AD`
long nPos; 57}q'84
:[&X*bw[
/_|1,x-Kx
public FileAccessI() throws IOException ?~{xL"
{ ^b#E%Rd
this("",0); ]=3O,\
} J@fE")
4SrK]+|
^s*} 0
public FileAccessI(String sName,long nPos) throws IOException VGq]id{*$
{ %Z? o]
oSavedFile = new RandomAccessFile(sName,"rw"); 2P}RZvUd
this.nPos = nPos; #wyS?FP-
oSavedFile.seek(nPos); UTt#ltun?
} Id0F2 [
;a`X|N9
ao!r6:&v$e
public synchronized int write(byte[] b,int nStart,int nLen) 5 $J
{ @6SSk=9_S
int n = -1; ik*_,51Zj
try{ ,L;vN6~
oSavedFile.write(b,nStart,nLen); ^q`*!B9@
n = nLen; Vmc)or*#
} ZJ(!jc$"*%
catch(IOException e) aBnbu vp
{ ccSSau5N
e.printStackTrace (); v#FUD-Z
} C(t/:?(y
#`$7$Y~]
luT8>9X^:a
return n; 86g+c
} c"ztrKQQ
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\YS?}! 0
} a5M>1&j/eC
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De_</1Au!2
/* as4NvZ@+r
**SiteInfoBean.java F?kVW[h?q
*/ @El<"\
package NetFox; *@nUas2"
?s]`G'=>V`
JPG!cX%
public class SiteInfoBean { 4/?Zp4g
)QD}R36Ic
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private String sSiteURL; //Site's URL $ Zr,-
private String sFilePath; //Saved File's Path ise}> A!t
private String sFileName; //Saved File's Name ,0bM*qob
private int nSplitter; //Count of Splited Downloading File MVdx5,t
:N}KScS|Wa
lijy?:__
public SiteInfoBean() cG:`Zj~4
{//nSplitter的缺省值为5 d ] ;pG(
//default value of nSplitter is 5 )[*O^bPowI
this("","","",5); pt#[.n#f
} |5Pbc&mH8A
kVv <tw
xF;v 6d
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1\0@?6`^
{ !%r`'|9y
sSiteURL= sURL; Rjl__90
sFilePath = sPath; :F=nb+HZ
sFileName = sName; H)Ge#=;ckQ
this.nSplitter = nSpiltter; P;&p[[7
N~jQ!y
m9@n
} su;S)yZb
a7G2C oM8
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public String getSSiteURL() dAl<'~g
{ Zd ,=
return sSiteURL; V bOLTc
} RfG$Px '
+hgCk87%#
,r;d{
public void setSSiteURL(String value) ]H~,K]@.
{ /H@")je
sSiteURL = value; v!A|n3B]p
} wtS*w
,&]` b#Rc
V JL;+
public String getSFilePath() W2h[NimU
{ l$_rA~Mo
return sFilePath; z&,sm5Lb
} Po.BcytM
\r,.hUp
$:II@=
public void setSFilePath(String value) #9VY[<
{ #/<Y!qV&
sFilePath = value; 4 GW[GT
} g}QTZT8
%W;Gf9.w
4ZpF1Zc4B
public String getSFileName() 5O ;^Mk|
{ z %E!tB2o
return sFileName; C&N4<2b
} s,H(m8#>
C)p<M H<
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public void setSFileName(String value) &W// Ox )f
{ iGVb.=)
sFileName = value; #-j! ;?
} B-'BJ|*4I
_4B iF?1
n@[</E(
public int getNSplitter() .BDRD~kB
{ TJS1,3<
return nSplitter; kTc5KHJ7
} F{~r7y;0
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public void setNSplitter(int nCount) {0WIDD
{ s^'#"`!v=
nSplitter = nCount; M`pTT5r
} oHd0 <TO
} +gCy@_2;
P Xn>x8z
1'm`SRX#e
/* {<4?o? 1g
**Utility.java 6@;L$QYY-V
*/ [k7N+W8
package NetFox; qZ_fQ@
`+BaDns
[3sxzU!t~
public class Utility { TxxB0
nk$V{(FJ
o+Ti$`2<O7
public Utility() ur,"K'w
{ bTy)0ta>AF
<;0N@
';|>`<
} {^5<{j3e
)k] !u
//线程睡眠 V3~a!k
public static void sleep(int nSecond) ^ R^N`V
{ B "F`OS[
try{ ^O Xr: P
Thread.sleep(nSecond); JKi@Kw
} ;4v}0N~.
catch(Exception e) P9mxY*K)%5
{ "q>I?UcZ
e.printStackTrace (); gXLZ)>+A+
} \{=`F`oB=
} m<,G:?RM
uQtk|)T E
//日志 <bXWkj
public static void log(String sMsg) S]%U]
{ Dw/Gha/
System.err.println(sMsg); \R>5F\ 0
} DEp%\sj?
lJ]\
4OZ5hH h
public static void log(int sMsg) mx(%tz^t
{ QDgEJ%U-
System.err.println(sMsg); |od4kt
} ;n7|.O]*
} R ms01m>Y
s.I1L?s1w?
pM'IQ3N
/* 5v>{Z0TE[6
**TestMethod.java qwNKRqT
*/ G9y12HV
package NetFox; NuS|X
{}J@+Zsi
(06Vcqg
public class TestMethod { ;ko[(eFN@
MLD>"W
"kBqY+:Cn
public TestMethod() _QMHPRELk
{ ///xx/weblogic60b2_win.exe _?]BVw
try{ fByh";<`P
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); l88a#zUQDN
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); fzFvfMAU
SiteFileFetch fileFetch = new SiteFileFetch(bean); R4~zL!7;
fileFetch.start(); Wt)SdF=U/
} @+\S!o3m
catch(Exception e){e.printStackTrace ();} 8}?Y;>s\
)lDIzLp
L^ #<HQ
} kulQR>u
ZYA.1VrM
7=p-A_X
public static void main(String[] args) 'D0X?2
{ R|)2Dg
new TestMethod(); |N=@E,33
} KIAe36.~
} ldCKSWIi-
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