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)); 5m_@s?P[
} oE5+
for(int i=0;i<nEndPos.length-1;i++) +[*UC"
{ }p "HD R>
nEndPos = nStartPos[i+1]; h; {?z
} R/P.m~?
nEndPos[nEndPos.length-1] = nFileLength; 8fdOV&&D~i
} 2Y$==j
} :S,#*rPKBK
1-q\C<Q)
Q9rE_}Z
//启动子线程 U~7.aZHPx3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $bD!./fl
for(int i=0;i<nStartPos.length;i++) [J:vSt
{ !WbQ`]uN/#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Th"7p:SE?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), r"rEVx#1=
nStartPos,nEndPos,i); ,E/vHI8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !&#CEF@J
fileSplitterFetch.start(); xv1$,|^ts
} $'e.bh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), QO|ODW+D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <01MXT-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", az`5{hK
nEndPos = " + nFileLength); 15SIZ:Q
// fileSplitterFetch[nPos.length-1].start(); CIV6Qe"<
'"I"D9;9
O1/!)E!
//等待子线程结束 @^`-VF
//int count = 0; SqEO ]~
//是否结束while循环 c-gaK\u}j}
boolean breakWhile = false; ^B5Hjf9
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1)k))w9
while(!bStop) G|H\(3hHLZ
{ Y/{Z`}
write_nPos(); #&DJ3(T
Utility.sleep(500); ,$CZ(GQ
breakWhile = true; 3aW4Gs<g
`L:wx5?
f!1KGP
for(int i=0;i<nStartPos.length;i++) u,&Z5S
{ W+Iln`L
if(!fileSplitterFetch.bDownOver) @Wdnc/o]
{ Z#\ \NfR
breakWhile = false; q^,^tw
break; UY>{e>/H9
} 783a Z8
} ,/Xxj\i
if(breakWhile) E?%k
break; 'zRd?Z>%
w}7`Vas9
SUx\qz)
//count++; *6k (xL
//if(count>4) c?wFEADn
// siteStop(); Kz'W |
} ujDAs%6MZ
S,J'Z:spf
M~3(4,
System.err.println("文件下载结束！"); MLL2V`vBT
} `t#C0
catch(Exception e){e.printStackTrace ();} 3{,Mpb@
} spAYb<
c*LnLK/m
[?;oiEe.|
//获得文件长度 eeuAo&L&
public long getFileSize() +>/Q+nh
{ ]_#[oS
int nFileLength = -1; W>s<&Vb
try{ EEF}Wf$f
URL url = new URL(siteInfoBean.getSSiteURL()); W*VQ"CW{^]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 48w3gye
httpConnection.setRequestProperty("User-Agent","NetFox"); m@"!=CTKd
M*@MkN*u&
e?F r/n
int responseCode=httpConnection.getResponseCode(); X/'B*y'=U
if(responseCode>=400) ?jb7Oq#[
{ $YL}rM
processErrorCode(responseCode); Jb_/c``
return -2; //-2 represent access is error >Utn[']~
} D|UDLaz~
<:/V`b3a
>>&~;PG[
String sHeader; [<OMv9(l'o
}8 ,b;Q
l$PO!JRD
for(int i=1;;i++) |RHX2sso
{ cj5pI?@e)
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :qw:)i
//Utility.log(in.readLine()); #16)7
sHeader=httpConnection.getHeaderFieldKey(i); vE{QN<6T
if(sHeader!=null) %lEPFp
{ YIjBKh
if(sHeader.equals("Content-Length")) c9DX
{ |1rBK.8
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 'gQm%:qU3r
break; LP.-
} =]"[?a >
} *:)#'cenI
else gl00$}C
break; `5h$@
} `s@1'IG;R_
} qAkx52v6
catch(IOException e){e.printStackTrace ();} _es>G'S
catch(Exception e){e.printStackTrace ();} |A &Nv~.)
YW>|gE
4dl?US[-
Utility.log(nFileLength); J6\<>5A?
B>-Iv_
} %rF}>$A
return nFileLength; 7Nx@eoZ
} wgfn:LR
jhK&Z7;
^Fy) oWS
//保存下载信息（文件指针位置） 0vDP-qJV-
private void write_nPos() Fx)]AJ~[t
{ +)Z,%\)Z
try{ D3BX[
output = new DataOutputStream(new FileOutputStream(tmpFile)); Sd}fse
output.writeInt(nStartPos.length); B*K%&w10~
for(int i=0;i<nStartPos.length;i++) /|BzpIfpN
{ b-%7@j
// output.writeLong(nPos); NIQa{R/H
output.writeLong(fileSplitterFetch.nStartPos); H=7dp%b"
output.writeLong(fileSplitterFetch.nEndPos); z_r W1?|
} %k1*&2"1#
output.close(); C$M^<z
} '$l*FWOEal
catch(IOException e){e.printStackTrace ();} (w@|:0t^y[
catch(Exception e){e.printStackTrace ();} u~% m(
} (w4#?_
m[]pIXc(
P?\rRB
//读取保存的下载信息（文件指针位置） cXtL3T+
private void read_nPos() Q >)?_O(
{ 1*G7Uh@K}
try{ T3wR0,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,tmo6D62
int nCount = input.readInt(); I0GL/a4s
nStartPos = new long[nCount]; Eq'YtqU
nEndPos = new long[nCount]; kRZ(
for(int i=0;i<nStartPos.length;i++) !X*L<)=nh
{ rDm>Rm=
nStartPos = input.readLong(); cb|`)"<HN
nEndPos = input.readLong(); K)@]vw/\
} H;Z{R@kf
input.close(); CM8WI~
} i8u9~F
catch(IOException e){e.printStackTrace ();} G8f7N;D
catch(Exception e){e.printStackTrace ();} rTW1'@E
} [ZDJs`h!`
I3s'44
i1C]bUXA
private void processErrorCode(int nErrorCode) '^lrGO6 z7
{ d<fS52~l
System.err.println("Error Code : " + nErrorCode); hW _NARA
} +1F@vag7
li,kW`j+t
eAm7*2
//停止文件下载 &Lk@Xq1
public void siteStop() Sg')w1
{ [uZU p*.V
bStop = true; />.&
for(int i=0;i<nStartPos.length;i++) 7u o4F=%
fileSplitterFetch.splitterStop(); mpK|I|-
t[)z/[m
x8tRa0-q
} \MK)dj5uUJ
} .#rI9op
//负责部分文件的抓取 'HPw5 L
**FileSplitterFetch.java #d(6q$IE
*/ XlDVJx<&J
package NetFox; V>4 !fD=
]wdudvS@6r
C'*1w
import java.io.*; #q(BR{A>t
import java.net.*; R*VZ=i
7A3e-51>
(:M6*RV
public class FileSplitterFetch extends Thread { \1ys2BX
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KDg!Y(m{
String sURL; //File URL rQN+x|dKMb
long nStartPos; //File Snippet Start Position %+xh
long nEndPos; //File Snippet End Position lT1*e(I
int nThreadID; //Thread's ID I{B8'n{cN
boolean bDownOver = false; //Downing is over klv^310
boolean bStop = false; //Stop identical Scxf5x-
FileAccessI fileAccessI = null; //File Access interface Y2<Z"D`
LEHlfB#z`@
$P4hNb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rbQA6_U 5A
{ BRD>q4w
this.sURL = sURL; r$G;^
this.nStartPos = nStart; lt5~rH2
this.nEndPos = nEnd; ag[yM
nThreadID = id; khc5h^0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \muyL?
} B~LB^ n(>@
;(VJZ_
M/Bn^A8@
public void run() pd>EUdbrp&
{ ^Q2K0'm5
while(nStartPos < nEndPos && !bStop) ?HZ+fS,-
{ :%!=Ej.J
~A>3k2N/e
>:KPvq!0
try{ 4'G<qJoc
URL url = new URL(sURL); Lr40rLx;u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Gd:fWz(
httpConnection.setRequestProperty("User-Agent","NetFox"); ;y4 "wBX
String sProperty = "bytes="+nStartPos+"-"; oA_AnD?G+
httpConnection.setRequestProperty("RANGE",sProperty); eEezd[p
Utility.log(sProperty); k<8:
w}oH]jVKL6
A-c3B+
InputStream input = httpConnection.getInputStream(); p.8G]pS
//logResponseHead(httpConnection); }SUe 4r&4}
pz.<5
aMh2[I
byte[] b = new byte[1024]; e?RHf_d3T-
int nRead; 1u)I}"{W>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) b3y@!_'c
{ ]*I&104{
nStartPos += fileAccessI.write(b,0,nRead); GS<,adD
//if(nThreadID == 1) =Lp0i9c
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^J@Y?CQl\
} [8O`VSV3
b`18y cVME
HO&#Lv
Utility.log("Thread " + nThreadID + " is over!"); xxiEL2"`>
bDownOver = true; Ler9~}\D
//nPos = fileAccessI.write (b,0,nRead); sE-"TNONZ
} {.Nt#l
catch(Exception e){e.printStackTrace ();} 0Oe@0L%^3"
} Z</$~ T
} ]UFf-
7NoB
\u",bMQF
//打印回应的头信息 6dq5f?w]
public void logResponseHead(HttpURLConnection con) A3M)yWq
{ 0m51nw~B
for(int i=1;;i++) a"#5JcR3
{ j.AAY?L
String header=con.getHeaderFieldKey(i); %J2u+K
if(header!=null) YX@[z 5*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mEhVc!
Utility.log(header+" : "+con.getHeaderField(header)); xjv?Z"X
else Q4_j`q
break; g%[lUxL
} E]_sl/`{od
} 5Lm ?
>|uZIcs 6
pkBmAJb@
public void splitterStop() a?\ Au
{ V4ayewVX
bStop = true; M^k~w{
} +r4^oT[-
GZ*cV3Y`&
Q6"r^wWx
} F9-xp7T
8Qek![3^
f>l}y->-Ug
/* ^EM##Ss_
**FileAccess.java Z`q?pE>R
*//文件访问(定位，写) @/B&R^aVZ
package NetFox; b.;F)(
import java.io.*; ks 3<zW(
e"[o2=v;5
X;ijCZb3b
public class FileAccessI implements Serializable{ A2*z
G#3 O^,m
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 0alm/or
RandomAccessFile oSavedFile; v34XcA
long nPos; v7xc01x
N\<M4fn
a:v&pj+|<
public FileAccessI() throws IOException %k5^n0|*
{ <|s|6C
this("",0); /_aFQ>.4n
} K`PF|=z
nwHi3ojD:
Xxp<qIEm
public FileAccessI(String sName,long nPos) throws IOException 3%!d&j>v
{ k+&LOb7
oSavedFile = new RandomAccessFile(sName,"rw"); r5tv9#4]
this.nPos = nPos; fh}\#WE"
oSavedFile.seek(nPos); WPpl9)Qc
} }\P9$D+
!NjC+ps]
I tp7X
public synchronized int write(byte[] b,int nStart,int nLen) Lc0^I<Y
{ "P"~/<:)
int n = -1; ?_}[@x
try{ $>]7NTP
oSavedFile.write(b,nStart,nLen); bC)diC
n = nLen; "*XR'9~7
} L%U-MOS=
catch(IOException e) qL UbRp
{ Ej8EQ%P
e.printStackTrace (); >&Y8VLcK
} (lTM^3 }
7`|$uIM`
$Rd74;edn
return n; f9X*bEl9;`
} 5e6]v2 k
y]+i.8[
yzgDdAM
} aQ46euth
Y(-4Agq
Y!Wz7 C
/* Mw*R~OX
**SiteInfoBean.java W6 f*>
*/ ?b:l.0m
package NetFox; egK,e?~
aOA;"jR1
d^!)',`
public class SiteInfoBean { 89k9#i X
~4`LOROC
-*M/,O
private String sSiteURL; //Site's URL 'k{pWfn=<
private String sFilePath; //Saved File's Path 8{(;s$H~
private String sFileName; //Saved File's Name p4*VE5[?_+
private int nSplitter; //Count of Splited Downloading File {ajaM'x
BXnSkT7
0[H'l",~
public SiteInfoBean() Ky|dRbK,
{//nSplitter的缺省值为5 @s b\0}
//default value of nSplitter is 5 VSL6tQp
this("","","",5); G=!Gy.
} J-au{eP^
#t>w)`bA-
&C`t(e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) AQDT6E:
{ wm=!tx\`k
sSiteURL= sURL; =3_I;Lw
sFilePath = sPath; ^Z$%OM,
sFileName = sName; Y?{L:4cRX
this.nSplitter = nSpiltter; hdXdz aNS
hg/G7Ur"
KtG|m'\D
} Uw8O"}U8
CC;T[b&
PeEC|&x
public String getSSiteURL() =EA*h_"q9
{ oe=^CeW"
return sSiteURL; PxhB=i!'$
} kXFgvIpg<
1 `hj]@.]
/EZF5_`bT
public void setSSiteURL(String value) MN}@EQvW==
{ BA4qQCS;5
sSiteURL = value; }S\\"SBC
} }Dc0 Y
sk5h_[tK
{0 IEizQ|i
public String getSFilePath() h# c.HtVE
{ ,edX;`#
return sFilePath; )hGRq'WA=
} wf)T-]e
Eaf6rjD
R^.E";/h
public void setSFilePath(String value) k|(uIU* ]
{ F*_g3K!!
sFilePath = value; xc7Wk&{=
} f02<u
K;a]+9C
*e&OpVn
public String getSFileName() &U^6N+l9
{ rvgArFf}]
return sFileName; ]?whx&+
} 8=Xy19<;t
s.d }*H-o
OSY$qL2
public void setSFileName(String value) 'H+H4(
{ _WO*N9Iz
sFileName = value; F'^6ra9
} ;7Cb!v1
tgCEz%
se(ZiyHp
public int getNSplitter() P~HzNC
{ Q(=} PF
return nSplitter; .Zv@iL5
} :Q@=;P2
ZCsL%(
FH:^<^M
public void setNSplitter(int nCount) UIPi<_Xa
{ 9#Gz2u$
nSplitter = nCount; mxt fKPb
} Y3KKskhLx
} .aTu]i3l_
E&ou(Q={
?WyL|;b*
/* s ~c_9,JK
**Utility.java FRqJ#yd]
*/ do@`(f3g
package NetFox; fG_.&!P
f86h"#4
=m]|C1x
public class Utility { 5$9g4
ye!}hm=w
lJ1_Zs `
public Utility() ZZ|a`U
{ 53=5xE= `D
nQm7At
KKB&)R
} *S,5
mux_S2x9m\
//线程睡眠 nW#UBtZ
public static void sleep(int nSecond) YL*yiZ9
{ 4&]Sb}
try{ `L n,qiA
Thread.sleep(nSecond); .hO) R.
} /E8{:>2
catch(Exception e) Jse;@K5y
{ CEbZj z|
e.printStackTrace (); aly1=j
} ;n1<1M>!
} ]'+PJdA
c4H5[LPF
//日志 _nW{Q-nh
public static void log(String sMsg) a^wGc+
{ g+'=#NS}
System.err.println(sMsg); ai|d`:;
} D2<(V,h9
#2AKO/
XL SYE
public static void log(int sMsg) W:s`;8iM$
{ ++{,1wY\
System.err.println(sMsg); v',%
} R<wPO-dX
} BCUn[4Gp
/~=W3lhY
[H"\<"1o
/* .%Pt[VQ
**TestMethod.java 5MU-Eu|*>
*/ dZ]['y%
package NetFox; e0rh~@E
Qy< ~{6V
ICq
public class TestMethod { vq(ElXTO
fSR+~Vy
x$p_mWC
public TestMethod() M`m-@z
{ ///xx/weblogic60b2_win.exe DNYJR]>
try{ hzv4+1Wd[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); MLVrL r t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1dsMmD[O
SiteFileFetch fileFetch = new SiteFileFetch(bean); $Sg5xkV,a
fileFetch.start(); =]Gw9sge@
} *SP@`)\D
catch(Exception e){e.printStackTrace ();} &:Mk^DH5
[22>)1<(
`Ckx~'1M:
} e$ pXnMx7
LHJ}I5zv
i"4&UJu1;
public static void main(String[] args) CSu}_$wC#
{ Obj?,O
new TestMethod(); =H8 LBM
} ?7?hDw_Nk
} IhRWa|{I
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