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)); IEJp!P,E
} IOi6' 1l
for(int i=0;i<nEndPos.length-1;i++) B|+tK
{ ;yK:.Vg
nEndPos = nStartPos[i+1]; #3act)m
} [XP3
nEndPos[nEndPos.length-1] = nFileLength; _w>9Z>PR
} cYMlcwS
} Q!dNJQpb
"Hw%@
Bn_@R`
//启动子线程 r)SwV!b
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; /R44x\nhr
for(int i=0;i<nStartPos.length;i++) L(!mm
{ Dx<CO1%z-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :X;AmLf`2u
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /IN/SZx
nStartPos,nEndPos,i); sd~T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =!%+ sem
fileSplitterFetch.start(); /K]<7
} oZ(T`5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {|J'd+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _GK3]F0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >HXmpu.O
nEndPos = " + nFileLength); +k4SN
// fileSplitterFetch[nPos.length-1].start(); h&6v&%S/L
*m[ow s
"?Cx4<nsM
//等待子线程结束 ?=h{`Ci^ $
//int count = 0; i@M^9|Gh
//是否结束while循环 D>Qc/+
boolean breakWhile = false; ;eRYgC
"*E%?MG
YSE6PG
while(!bStop) 7!E?(3$#"
{ 9}2E+
write_nPos(); X4R+Frt8
Utility.sleep(500); }6Uw4D61
breakWhile = true; 'M#'BQQ5
|VL(#U
Q+\?gU]
for(int i=0;i<nStartPos.length;i++) D,rs)
{ 0FV?By
if(!fileSplitterFetch.bDownOver) LGm>x
{ -a[]#v9
breakWhile = false; &m6x*i-5\f
break; 75V?K
} >9.xFiq<
} WurpHOJt+
if(breakWhile) ~D)!zQkD
break; zU9G:jH
kG7q4jFwP
C +%&!Q
//count++; zU'\r~c
//if(count>4) &&;ol}W
// siteStop(); .hxcx>%
} |E)Es!dr
'MHbXFM
xNh#=6__9
System.err.println("文件下载结束！"); dik+BBu5z
} xED`8PCfu
catch(Exception e){e.printStackTrace ();} 8@|rB3J
} }'KVi=qnHb
|QvG;{!
{zc<:^r^
//获得文件长度 6"Km E}
public long getFileSize() _ s]=g
{ heliL/
int nFileLength = -1; >k?/'R
try{ ~_TmS9
URL url = new URL(siteInfoBean.getSSiteURL()); ?N,'1I
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 38%xB<Y
httpConnection.setRequestProperty("User-Agent","NetFox"); E Cx_ [|3{
Dm j^aFB0|
F-)lRGw
int responseCode=httpConnection.getResponseCode(); zOpl#%"
if(responseCode>=400) L$GhM!c
{ yVyh'd:Ik
processErrorCode(responseCode); M[ (mH(j
return -2; //-2 represent access is error ,HEx9*E/s
} e4V4%Qw
AT:T%a:G?
>69+e+|I
String sHeader; $Wy7z^t
nz|;6?LCLY
NW`.RGLI<
for(int i=1;;i++) q9RCXo>Y+1
{ d]OoJK9&&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u":D{+wC|
//Utility.log(in.readLine()); ^IxT.g
sHeader=httpConnection.getHeaderFieldKey(i); B8^tIq
if(sHeader!=null) ,*2%6t`N?
{ UlHRA[SCv
if(sHeader.equals("Content-Length")) Ek+L"7
{ %($qg-x
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); YWSo:)LY
break; pCz;km
} "msCiqF{z
} x=yU }lsV
else x-0IxWD%
break; <_02)6j
} J<Wz3}w6
} aXyu%<@k
catch(IOException e){e.printStackTrace ();} fv!l{
catch(Exception e){e.printStackTrace ();} ujZki.x
,|_ewye
:z%vNKy1
Utility.log(nFileLength); &+-ZXN
>eg&i(C+
sQ/7Mc
return nFileLength; n*^g^gp
} ei;wT
zYdSg<[^
~F*pV*
//保存下载信息（文件指针位置） h'<}N
private void write_nPos() F_!6C-z
{ GV1\8OG7
try{ QeA)@x.p
output = new DataOutputStream(new FileOutputStream(tmpFile)); K6kPNi
output.writeInt(nStartPos.length); i+yqsYKO
for(int i=0;i<nStartPos.length;i++) :b;2iBVB
{ p#O#MN*
// output.writeLong(nPos); zh'TR$+\hO
output.writeLong(fileSplitterFetch.nStartPos); /I
output.writeLong(fileSplitterFetch.nEndPos); =y8HOT}8
} ^>uzMR!q5
output.close(); pvTV*
} #lQbMuR
catch(IOException e){e.printStackTrace ();} }$V]00 X
catch(Exception e){e.printStackTrace ();} 5j`"@C5;O
} Phl't~k
k0?4vA
tnbaU%;|J
//读取保存的下载信息（文件指针位置） L1`^~m|
private void read_nPos() x{u_kepv[k
{ ?L#C'Lz2+
try{ t'4hWNR'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8Uvf9,I'
int nCount = input.readInt(); ,JT|E~P?8
nStartPos = new long[nCount]; k+44ud.j
nEndPos = new long[nCount]; sMli!u
for(int i=0;i<nStartPos.length;i++) #$%9XD3
{ ~)D2U:"^xm
nStartPos = input.readLong(); C81+nR
nEndPos = input.readLong(); kf0zL3|
} ?V#%^ 57p
input.close(); $Vbgfp~U-
} 673v
catch(IOException e){e.printStackTrace ();} _%!C;`3Y
catch(Exception e){e.printStackTrace ();} F8YD:
} q|om^:n.
~R/7J{Sg
gE JmMh
private void processErrorCode(int nErrorCode) m:/@DZ
{ "j3Yu4_ks
System.err.println("Error Code : " + nErrorCode); |Wj)kr !|
} F {]:
ExI?UGT
bXc7$5(!VB
//停止文件下载 @g[p>t> *
public void siteStop() GY<Y,
{ *-Y77p7u
bStop = true; P$2J`b[H$
for(int i=0;i<nStartPos.length;i++) 2Y&z}4'j
fileSplitterFetch.splitterStop(); 8 +xLi4Pw
WE4:Jy
iBxCk^
} B+ GPTQSTb
} WW@/q`h
//负责部分文件的抓取 jfl7L"2
**FileSplitterFetch.java AZorzQ]s
*/ u~Q0V J~
package NetFox; B8Jev\_
0gHJ%m9s
w@.E}%bwq
import java.io.*; ):&A\nb
import java.net.*; I'BoP
DyG3|5s1R
8;p6~&).C~
public class FileSplitterFetch extends Thread { kX\t0'=]
J7emoD[
,Zzh.z::D
String sURL; //File URL X6!u(plVQ
long nStartPos; //File Snippet Start Position &pK1S>t
long nEndPos; //File Snippet End Position <|Bh;;
int nThreadID; //Thread's ID O9A.WSJ >}
boolean bDownOver = false; //Downing is over d4[M{LSl
boolean bStop = false; //Stop identical 0Apdhwk~
FileAccessI fileAccessI = null; //File Access interface ~y_TT5+3
+uKlg#wqc
xx nW1`]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `f*?|)
{ e<l Wel
this.sURL = sURL; DM!vB+j+,
this.nStartPos = nStart; #It{B
this.nEndPos = nEnd; aT(Pf7 O
nThreadID = id; '%V ;oJ"
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zkI\ji
} <N=p_m 2T
C$aiOK-]+
8~EDmg[
public void run() /%$'N$@f
{ `9s5 *;Z
while(nStartPos < nEndPos && !bStop) rgB`<[:b
{ fa/ '4
J@H9nw+Q
W*u Yb|0
try{ 9X@y*;w<t
URL url = new URL(sURL); :bW}*0b-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Tf.KUm
httpConnection.setRequestProperty("User-Agent","NetFox"); mDvZ1aj
String sProperty = "bytes="+nStartPos+"-"; d vkA-9
httpConnection.setRequestProperty("RANGE",sProperty); QT9(s\u
Utility.log(sProperty); G#Nh)ff
. CLiv
=:1f 0QF
InputStream input = httpConnection.getInputStream(); 3kdTteyy+
//logResponseHead(httpConnection); j?+FS`a!
4bhm1Q
y{s?]hLk
byte[] b = new byte[1024]; 1*[h$Z&H?
int nRead; t\CVL?e`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5(%+8<2
{ NV9D;g$Y
nStartPos += fileAccessI.write(b,0,nRead); b@Ik c<
//if(nThreadID == 1) OlRBvfoh8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k^p|H:
} MH'S,^J
Mm:6+
.O3i"X]
Utility.log("Thread " + nThreadID + " is over!"); pYI`5B4
bDownOver = true; P@lExF*D1:
//nPos = fileAccessI.write (b,0,nRead); `T{{wty
} d&(GIH E&d
catch(Exception e){e.printStackTrace ();} X{9D fgW
} (JocnM|U
} VDx=Tsu-
TRcY!
:upi2S_e
//打印回应的头信息 \Z ] <L
public void logResponseHead(HttpURLConnection con) O:+#k-?
{ <3LyNG.
for(int i=1;;i++) KU"?ZI
{ vZTX3c:,1
String header=con.getHeaderFieldKey(i); s)_7*DY
if(header!=null) ]V<[W,*(5
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :w#Zs)N
Utility.log(header+" : "+con.getHeaderField(header)); Ii,e=RG>
else {|^9y]VFu
break; Um4 }`
} tUGnD<P
} s59v* /
*["9;_KD
YnNB#x8|
public void splitterStop() Fm`hFBKW
{ y)"aQJ>
bStop = true; Qa5<go{
} 9 @!Og(l
LU?X|{z
KY!
} sI@m"A
ZQD_w#0j
0X~
/* TixHEhw
**FileAccess.java gkI(B2,/
*//文件访问(定位，写) mSY;hJi
package NetFox; Ss@\'K3e
import java.io.*; PQa{5"
KX"?3#U#Fm
fYuJf,I[f
public class FileAccessI implements Serializable{ j_L 'Ztu3
hW~,Uqy
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fv5'Bl
RandomAccessFile oSavedFile; w+=>b
long nPos; rG:IS=
*%:p01&+
ZC_b`q<
public FileAccessI() throws IOException c;xL.
{ d}EGI
this("",0); z;zyk
} ?uc=(J+6
hvtg_w6K
6|V713\
public FileAccessI(String sName,long nPos) throws IOException <?yAIhgN*
{ eZ[CqUJ&
oSavedFile = new RandomAccessFile(sName,"rw"); ^cZF#%k
this.nPos = nPos; 6Hi3h{
oSavedFile.seek(nPos); jJQ6]ucwa
} \tye:!a?;@
I?G m
H~i+:X=I
public synchronized int write(byte[] b,int nStart,int nLen) 8v8?D8\=|
{ 5,:>.LRA
int n = -1; .</d$FM JE
try{ c+f~>AaI
oSavedFile.write(b,nStart,nLen); #|v\UJ:Pf/
n = nLen; L}h?nWm8
} ~%qHJ4C
catch(IOException e) _"&b%!
{ azr|Fz/
e.printStackTrace (); %Nwap~=H;
} S)iv k x
3Nd&*QSV
SpdQ<]
return n; EFW'D=&h8
} <ap%+(!I
i~@e}=
y1p^ &9U
} "diF$Lj
`J|bGf#
|#D3~au
/* WogJ~N,d53
**SiteInfoBean.java VE+Q Y9(
*/ :XxsDD
package NetFox; BKPXXR
+7U$qEG
Yz us=
public class SiteInfoBean { ?[hIv6c
+;c)GNQ)6:
H{VVxj
private String sSiteURL; //Site's URL .}&bE1
private String sFilePath; //Saved File's Path 'H`aQt+
private String sFileName; //Saved File's Name e[$=5U~c
private int nSplitter; //Count of Splited Downloading File 8)s}>:}
3Wa^:8N
mDEO$:A
public SiteInfoBean() Di5eD,N
{//nSplitter的缺省值为5 dZFf/BXU
//default value of nSplitter is 5 7;:R\d6iL
this("","","",5); EdlU}LU
} 2.{:PM4Z4
|Gx-c ,{{
OCnQSkj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QFY1@2EC
{ F"FGPk
sSiteURL= sURL; )cJ9YKKy
sFilePath = sPath; zlco?Rt
sFileName = sName; =3$JeNK9
this.nSplitter = nSpiltter; O68/Hf1W
,j>A[e&.
/oKa?iT
} @d:TAwOI'
#!wu}nDu
qPDe;$J)
public String getSSiteURL() }enm#0Ha
{ {U?/u93~
return sSiteURL; hm*1w6 =
} )D\!#<#h
X31[
rV*9=
public void setSSiteURL(String value) 8fRk8
{ rJH u~/_Dq
sSiteURL = value; V*5 ~A[r
} 3B8\r}L
]&w8"q
Vr@I9W;D#
public String getSFilePath() \B/+.\
{ lqh+yX%*
return sFilePath; \CNv,HUm3
} J5e
[vh&o-6
{Z%4Pg
public void setSFilePath(String value) }iZO0C
{ 2L Kpwz?
sFilePath = value; L}NckL
} P>n}\"z4
qIIc>By(\"
g\^7Q
public String getSFileName() "i0{E!,XL
{ ,j\1UAa
return sFileName; =$xxkc.~G
} @'>h P
^h #0e:7<
7%DA0.g
public void setSFileName(String value) "I+71Ce
{ }TE4)vXs
sFileName = value; 7vO3+lT/Y;
} S bI7<_
E>>@X^ =
LgFF+z
public int getNSplitter() qM%l
{ {WJ9!pA!lk
return nSplitter; x.W93e[]H
} ;U$Fz~rJ
4+46z|
1~rZka[s
public void setNSplitter(int nCount) R@zl?>+
{ xNDX(_U>\
nSplitter = nCount; f/+UD-@%m
} OwRH :l
} 7HfA{.|m
ip.aM#
${fJ]
/* (Klvctoy
**Utility.java =, kH(rp2
*/ 4'EC(NR7N
package NetFox; kq+`.
2smQD8t
Y6<"_
public class Utility { 93I.Wp_{
>Z%qkU/
EhJpJb[Z
public Utility() vhsHyb
{ ]1YyP
v:.`~h/b
MYI*0o;
} j!m42
>Vp#
//线程睡眠 A_nu:K-
public static void sleep(int nSecond) jiAKV0lX W
{ Ek#?B6s
try{ Qmbl_#
Thread.sleep(nSecond); hf#[Vns
} LYM(eK5V
catch(Exception e) &.D#OnRh9
{ ]CLt Km
e.printStackTrace (); XNZW J
} s,~)5nL
} >2kjd
Owt|vceT
//日志 f\cm84
public static void log(String sMsg) v>ygr8+C,
{ [&_c.ti
System.err.println(sMsg); FH Hi/yh
} (c3%rM m]
>U4hsr05
#0*OkZMt
public static void log(int sMsg) Dq$co1eT
{ R>|)-"b( `
System.err.println(sMsg); 6,J:sm\
} $<c;xDO&t
} 0xZX%2E
7R4xJ H
-`d9dJ dB
/* `-,yJ
**TestMethod.java 7|vB\[s
*/ ;`CNe$y
package NetFox; T1Gy_ G/
;Nfd
fG{ 9doUD
public class TestMethod { d]bM,`K* 6
H6fR6Kr4j
XMJEIG
public TestMethod() sD_"
{ ///xx/weblogic60b2_win.exe OsSGVk #Qh
try{ gJkvH[hDY
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X.YMb .\<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *d%U]Hby,
SiteFileFetch fileFetch = new SiteFileFetch(bean); v8PH(d2{@
fileFetch.start(); t93iU?Z
} wfE%` 1
catch(Exception e){e.printStackTrace ();} Z{#;my*X|
B%~D`[~?
\@%sX24D
} ~-dL #;
sPKyg
moe5H
public static void main(String[] args) B^{87YR
{ +0)zB;~7
new TestMethod(); F~qiNV
} (";{@a %
} d7O\p(M1
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