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)); 6M"]p
} 6|05-x|
for(int i=0;i<nEndPos.length-1;i++) $H/3t?6h`
{ ~PUz/^^ s
nEndPos = nStartPos[i+1]; w$7*za2
} 33\{S$p
nEndPos[nEndPos.length-1] = nFileLength; \HDRr*KO
} )jp#|#h
} 6P' m0
<3QE3;4
tWi@_Rlx;
//启动子线程 }0T1* .Cz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; i+&*W{Re
for(int i=0;i<nStartPos.length;i++) =@m|g )
{ .h^."+TJ
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), -O_5OT4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Od'!v&
nStartPos,nEndPos,i); ?0+D1w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); er}/~@JJ
fileSplitterFetch.start(); 1dOVH7
} ]7ROCJ;
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u|\Lb2Kb:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +"a .,-f!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~)}npS;
nEndPos = " + nFileLength); D:llGdU#2
// fileSplitterFetch[nPos.length-1].start(); ;KmSz 1A
POc< G^
~l-Q0wg
//等待子线程结束 "}|n;:r
//int count = 0; Hq^sU%
//是否结束while循环 >U9*
boolean breakWhile = false; r9G<HKl
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g!<@6\RB
while(!bStop) .8CR \-
{ l?B\TA^
write_nPos(); lC.Yu$O5
Utility.sleep(500); @Q3aJ98)2
breakWhile = true; &?*M+q34
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for(int i=0;i<nStartPos.length;i++) ekfD+X
{ u9e A"\s
if(!fileSplitterFetch.bDownOver) r9@W8](\
{ b IcLMG s
breakWhile = false; }(dhXOf\q
break; lx~!FLn
} Ud:v3"1
} rU5gQq;
if(breakWhile) .8l\;/o|
break; \Btv76*,
&D uvy#J
u%#bu^4"
//count++; Z*nC ;5Kd
//if(count>4) ;]MHU/
// siteStop(); $r9Sn
} H(!)]dO
8OZc:/
U=p,drF,A
System.err.println("文件下载结束！"); A5+vzu^
} PV>-"2n
catch(Exception e){e.printStackTrace ();} .wx;!9
} zO2Z\E'%.
Zo22se0)
nvxftbfE^D
//获得文件长度 N9Yc\?_NU_
public long getFileSize() Tul_/`An
{ |~CN]N
int nFileLength = -1; ;58l_ue
try{ 7f'9Dm`
URL url = new URL(siteInfoBean.getSSiteURL()); RT8xU;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yEy} PCJ&
httpConnection.setRequestProperty("User-Agent","NetFox"); 2Q)"~3
rFSLTbTf
*8fnxWR
int responseCode=httpConnection.getResponseCode(); @P4fR7
if(responseCode>=400) Tl%#N"
{ d5%A64?
processErrorCode(responseCode); |SZRO,7x
return -2; //-2 represent access is error @X"p"3V
} a84^"GH7
l[l('-f
SPeSe/
String sHeader; 6YQ&+4
sE-E\+
[(5;jUmF@
for(int i=1;;i++) !t{3IE
{ Ytc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); D&/(Avx.
//Utility.log(in.readLine()); ^~0\d;l_
sHeader=httpConnection.getHeaderFieldKey(i); *n N;!*J
if(sHeader!=null) $985q@pV0
{ Ja|! fT
if(sHeader.equals("Content-Length")) ,-&ler~[
{ VieC+Kk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $[6:KV
break; _LFZ0
} !!b5vzyve
} Ni'vz7j
else #q%xJ[
break; c</d1xT
} OnC|9
} ]ZelB,7q
catch(IOException e){e.printStackTrace ();} amK?LDf]
catch(Exception e){e.printStackTrace ();} Ajr]&H4
ce/Rzid
bPAp0}{Fu
Utility.log(nFileLength); :O{`!&[>L
*{P"u(K
,o]"G[Jk
return nFileLength; v-3In\T=^
} jmmm0,#D
bg*4Z?[dd
:kfHILi
//保存下载信息（文件指针位置） 07DpvhDQ
private void write_nPos() @|6n.'f+
{ @>_`g=
try{ B@Ez,u5
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3 ~0Z.!O
output.writeInt(nStartPos.length); G)';ucs:,
for(int i=0;i<nStartPos.length;i++) &7!&]kA+
{ ~&[Wqn@MZ
// output.writeLong(nPos); 3gaijVN
output.writeLong(fileSplitterFetch.nStartPos); <- Q=h?D
output.writeLong(fileSplitterFetch.nEndPos); r ioNP(
} 'xm_oGWE
output.close(); b{=2#J-
} 8 qt,sU
catch(IOException e){e.printStackTrace ();} '^'vafs-/@
catch(Exception e){e.printStackTrace ();} M%7{g"J*
} 9Ruj_U
;"hED:z6%
+u#;k!B/>
//读取保存的下载信息（文件指针位置） ,OsFv}v7
private void read_nPos() Eg-3GkC
{ B\wH`5/KW
try{ 7c1xB.g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Gy hoo'<
int nCount = input.readInt(); r`pg`ChHv
nStartPos = new long[nCount]; zdrCr0Rx,
nEndPos = new long[nCount]; &*B=5W;6^u
for(int i=0;i<nStartPos.length;i++) 2--"@@
{ 3k py3z[%
nStartPos = input.readLong(); jxU1u"WU
nEndPos = input.readLong(); %Wkvo-rOq
} ;t{Ew+s
input.close(); dFFJw[$8w
} Q<3=s6@T
catch(IOException e){e.printStackTrace ();} XZLo*C!MG
catch(Exception e){e.printStackTrace ();} @tWyc%t
} cJd~UQ<k
t8DySFT
iUJqAi1o
private void processErrorCode(int nErrorCode) {5QIQ
{ IqJ7'X
System.err.println("Error Code : " + nErrorCode); uIvy1h9m
} 0tv"tA;
ce{(5IC
m_\w)
//停止文件下载 SCs@Q
public void siteStop() T3,"g=
{ 2`tdH|Z`
bStop = true; "5"6mw?
for(int i=0;i<nStartPos.length;i++) @r]wZ~@
fileSplitterFetch.splitterStop(); x*Y&s<
:p0|4g
:'9%~q.D4
} HpSmB[WF
} o?$kcI4
//负责部分文件的抓取 ]ppi962Z
**FileSplitterFetch.java +dw$IMwb
*/ tfW/Mf
package NetFox; swJ3_WhbdT
\Y&*sfQ
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import java.io.*; CB{%~
import java.net.*; ="<5+G
6!bp;iLKy
ifTMoC%
public class FileSplitterFetch extends Thread { R]O!F)_/'
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rxH*h`Xx@
String sURL; //File URL 9otA5I^v
long nStartPos; //File Snippet Start Position 23 j{bK
long nEndPos; //File Snippet End Position SQhk)S
int nThreadID; //Thread's ID wDswK "T
boolean bDownOver = false; //Downing is over T+ey>[
boolean bStop = false; //Stop identical ,ef"S r
FileAccessI fileAccessI = null; //File Access interface }'mVD^<+
WJbdsPs
?K%&N99c!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException /fC@T
{ M3c!SXx\
this.sURL = sURL; KKP}fN
this.nStartPos = nStart; f_a.BTtNO
this.nEndPos = nEnd; Pj9n`LwM
nThreadID = id; 8.FBgZh*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )nmLgsg
} ):OGhWq
NSH20$A<
}_93}e
public void run() B?`n@/
{ rqbX9M^
while(nStartPos < nEndPos && !bStop) _9!*laR!2
{ 8 #fzL7
&$F4/2|b%
2g5Ft
try{ ^HYmi\`
URL url = new URL(sURL); UQ6UZd37
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [ fvip_Pt
httpConnection.setRequestProperty("User-Agent","NetFox"); D-\WS^#
String sProperty = "bytes="+nStartPos+"-"; M:x?I_JG8
httpConnection.setRequestProperty("RANGE",sProperty); u&/[sqx
Utility.log(sProperty); sk !92mQ
v$c*3H.seM
fq(r,h=|
InputStream input = httpConnection.getInputStream(); 4Kjrk7GAx
//logResponseHead(httpConnection); $MD|YW5
g&9E>wT
,0+%ji^V
byte[] b = new byte[1024]; H%N!;Jz=
int nRead; par|j]
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) gI8r SmH
{ ^% y<7>%
nStartPos += fileAccessI.write(b,0,nRead); #eSVFD5ZU
//if(nThreadID == 1) q>:>f+4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d'ddxT$GG
} ;AyE(|U+
W/_=S+CvK
F[PIo7?K
Utility.log("Thread " + nThreadID + " is over!"); [<SM*fQ>t
bDownOver = true; 6v~` jS%3
//nPos = fileAccessI.write (b,0,nRead); y,&.<Yc
} pW ]+a0j
catch(Exception e){e.printStackTrace ();} P\<dy?nZ
} N2:};a[ui5
} `L p3snS
XQL"D)fw
#?%akQ+w
//打印回应的头信息 KWtLrZ(j
public void logResponseHead(HttpURLConnection con) rmpx8CY"
{ k8fvg4
for(int i=1;;i++) o=i)s2
{ +E8\g
String header=con.getHeaderFieldKey(i); (2J_Y*N~>
if(header!=null) n';"c;Ye)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |O0=Q,<m
Utility.log(header+" : "+con.getHeaderField(header)); *:t]|$;E\
else i!8 o(!I
break; ~5Wr |qg%{
} 'Gwa[ |6i
} wn*<.s
0l-m:6
U 7mA~t2E
public void splitterStop() mNkS!(L6
{ LB`=+FD
bStop = true; }G^Bc4@b
} 0CXh|AU
p\lS)9
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} 2q}M1-^
_4qP0LCa
|lH~nU.*
/* A*l(0`aWq
**FileAccess.java v_Om3i9$E
*//文件访问(定位，写) +zodkB~)
package NetFox; K"'W4bO#7
import java.io.*; &8!*u3
c%1<O!c
Q*wub9
public class FileAccessI implements Serializable{ "=)i'x"0"
W[S4s/)mg
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _r!''@B
RandomAccessFile oSavedFile; o6f^DG3*
long nPos; w)I!q&`Y
=6j4_+5mnH
Ao%E]M
public FileAccessI() throws IOException 2`4'Y.Qf
{ > Q1r^
this("",0); ~F7 +R
} ~doOt
# Sfz^
#fgRF
public FileAccessI(String sName,long nPos) throws IOException @kU{
{ ydp?%RB3w
oSavedFile = new RandomAccessFile(sName,"rw"); HfN-WYiR
this.nPos = nPos; 9/Q_Jv-Q
oSavedFile.seek(nPos); Bkg/A;H
} U" eP>HHp
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$Yfm>4
public synchronized int write(byte[] b,int nStart,int nLen) EoLF7j<W
{ lhZWL}l
int n = -1; 1B~H*=t4h
try{ [ bv>(a_,
oSavedFile.write(b,nStart,nLen); oQJK}9QR
n = nLen; 9vc3&r
} arf`%9M
catch(IOException e) 77/&M^0
{ ) *:<3g!
e.printStackTrace (); a&YD4DQ05
} }>:v
_2{i}L
.S/W_R
return n; dP0!?J Y
} /|] %0B
Ko%&~C_
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} b6=.6?H@4f
k#k!AcC
42:~oKiQ$"
/* k,0RpE
**SiteInfoBean.java (bH*i\W
*/ [sG=(~BU
package NetFox; WE$Pi;q1
w?kdM1T
Zcd!y9]#
public class SiteInfoBean { 31mY]Jve"
pE>~F
e#`wshtN:
private String sSiteURL; //Site's URL T1m097
private String sFilePath; //Saved File's Path !Dp4uE:Pq
private String sFileName; //Saved File's Name YIs(Q
private int nSplitter; //Count of Splited Downloading File Qg
Y604peUF
>*%ySlZbs
public SiteInfoBean() l= 5kd.{
{//nSplitter的缺省值为5 xy`aR< L
//default value of nSplitter is 5 C/dqCUX:
this("","","",5); lPm'>,}Y
} _[h1SAJ
Cec!{]DL&
YBQO]3f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N(mhgC<O
{ -[OGZP`8
sSiteURL= sURL; }8 A]
sFilePath = sPath; pLMki=.Ld
sFileName = sName; eG26m_S=
this.nSplitter = nSpiltter; @V)k*h3r+
6TS+z7S81L
ewB&PR
} }S'+Ytea
s9) @$3\
WQ4:='(
public String getSSiteURL() 4A0R07"
{ e#L/
return sSiteURL; 7dI+aJ
} Sj{z
VR5$[-E3
$Hqm 09w
public void setSSiteURL(String value) S:{hgi,T*
{ [r_,BH\nu
sSiteURL = value; m *8[I
} O?NAbxkp
lwPK^)|}
I"*g-ji0
public String getSFilePath() /HH5Mn*
{ yNdtq\h
return sFilePath; _7.Wz7]b
} Sai_rNRWB
2;.7c+r0
-fVeE<[
public void setSFilePath(String value) lY!`<_Am
{ l/;OC
sFilePath = value; oH!sJ&"#_
} Z 2Fm=88
%b'ic
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public String getSFileName() 2H fP$.
{ wG2lCv`d
return sFileName; ON _uu]=
} G\tTwX4
%).phn"ij[
<||F$t
public void setSFileName(String value) i{PRjkR
{ g;w4:k)U
sFileName = value; ^#e:q
} /lDW5;d
i>r4Rz!
^sd+s ~xx
public int getNSplitter() NS6Bi3~
{ zAt!jP0E
return nSplitter; CF>k_\/Bj
} S(mJ;C
Ta?#o
5+:b#B
public void setNSplitter(int nCount) ]"q[hF*PM
{ ULMG"."IH
nSplitter = nCount; Sj(uc#
} sIdo(`8$
} l*("[?>I
N:[m,U9a
^CI.F.#X|
/* %k{~Fa
**Utility.java g1muT.W]S
*/ r Y|'<$wvg
package NetFox; eV^@kI4
O[y.3>l[s
IPa08/
public class Utility { LslQZ]3MY
`R0>;TdT
L7_Mg{
public Utility() U2/H,D
{ 75wQH*
`23&vGk}
)y'`C@ijI
} r vVU5zA4H
e{U`^ao`F8
//线程睡眠 IB /.i(
public static void sleep(int nSecond) QkZT%!7
{ =#n05*^
try{ e"hm|'
Thread.sleep(nSecond); Yi&;4vC
} V\%;S
catch(Exception e) f!e8xDfA
{ #>O,w0<qM
e.printStackTrace (); UP 1Y3
} W"AWhi{h
} 2:MB u5**
3X*;.'#Z
//日志 f( hK>H
public static void log(String sMsg) fo&q/;l\
{ !0c7nzjm
System.err.println(sMsg); >BMJA:j
} :aLShxKA
gWqmK/.U.0
)Ac8'{Tq/
public static void log(int sMsg) j#Ly!%dp
{ 5|x&Z/hL
System.err.println(sMsg); 7!hL(k[
} 6Bmv1n[X^h
} }lML..((1
7'7bIaJk
3l->$R]
/* kI]i,v#F
**TestMethod.java 5&v'aiWK
*/ tz j]c
package NetFox; 8|{:N>7
X}0NeG^'O
a2vUZhkR
public class TestMethod { jWiZ!dtUZ
,;;M69c[ x
7 ;|jq39
public TestMethod() N'Ywn}!js
{ ///xx/weblogic60b2_win.exe F0o7XUt
try{ +VDwDJ)lG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); dP T)&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .hn{m9|U
SiteFileFetch fileFetch = new SiteFileFetch(bean); pnca+d
fileFetch.start(); )"|'=
} (k6=o';y
catch(Exception e){e.printStackTrace ();} /],:sS7
;"!dq)
44f8Hc1g
} n0 _:!]k^
eT[,k[#q
f?#:@ zcL
public static void main(String[] args) s#&jE GBug
{ ?JzLn,&
new TestMethod(); g?A4C`l6iy
} J*U,kyYF
} j7<`^OG
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