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)); D *IeG>%
} L+eK)Q
for(int i=0;i<nEndPos.length-1;i++) lkC|g%f
{ Wtp=1
nEndPos = nStartPos[i+1]; J|@D @\?7
} 3o"l sly
nEndPos[nEndPos.length-1] = nFileLength; +}Mm5^6*
} ?.n1t@sG&
} \j &&o
<GLoTolZ
",#Ug"|2
//启动子线程 vNdW.V}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P>^$X
for(int i=0;i<nStartPos.length;i++) jhBfy|Ftu
{ P*OT&q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %!A-K1Z\D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), InRcIQT
nStartPos,nEndPos,i); L3 KJ~LI
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;0NJX)GL
fileSplitterFetch.start(); J6ed
} t<RPDQ>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Kaaz,C.$^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ="PFCxi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XqwP<5Z
nEndPos = " + nFileLength); .F[5{XV
// fileSplitterFetch[nPos.length-1].start(); Wg<o%6`
66$hdT$
DF'~ #G8
//等待子线程结束 hlz/TIP^N3
//int count = 0; 4/v[.5
//是否结束while循环 ~QUN O~
boolean breakWhile = false; c%&*yR
kuq&; uk$Q
06v'!M
while(!bStop) >%slzr
{ }o\} qu*
write_nPos(); 6Q{OM:L/;.
Utility.sleep(500); mS49l
breakWhile = true; HiD%BL>%
$BG]is,&5
f zL5C2d
for(int i=0;i<nStartPos.length;i++) = C/F26=|
{ } :gi<#-:G
if(!fileSplitterFetch.bDownOver) [HQ/MkP-Z
{ }_H\75Iv
breakWhile = false; %?F$3YN,
break; ^+gD;a|t
} NzN"_ojM
} NLUO{'uUW
if(breakWhile) P{Q$(rOe
break; *i!t&s
] ;HCt=I~
J4 U]_|
//count++; ;Cjj_9e,:
//if(count>4) dxH.
// siteStop(); y(E<MRd8V
} -Rr !J37
V 'fri/Z
8Z)wot
System.err.println("文件下载结束！"); NS;LFeGD
} bfpoX,:
catch(Exception e){e.printStackTrace ();} 1N5lI97j
} -.L )\
09{s'
U!E}(9 tb
//获得文件长度 563ExibH
public long getFileSize() N^k& 8
{ 7{9M ^.}
int nFileLength = -1; v yt|x5
try{ <'BsQHI
URL url = new URL(siteInfoBean.getSSiteURL()); .CNwuN\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); FPPl^
httpConnection.setRequestProperty("User-Agent","NetFox"); rEbH<|
.'h^
oiD{Z
int responseCode=httpConnection.getResponseCode(); ub+XgNO
if(responseCode>=400) G|||.B8
{ pRUQMPn (
processErrorCode(responseCode); 6z:/ma^
return -2; //-2 represent access is error SwaPRAF
} {.DY\;Q
^+k= ;nl
bqaj~:}@
String sHeader; H]f[r~
TefPxvd
)HvBceN
for(int i=1;;i++) h-SKw=n
{ 6Tc!=lk
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); E}<i?;
//Utility.log(in.readLine()); ~&+a.@T
sHeader=httpConnection.getHeaderFieldKey(i); eZ0-O /_i
if(sHeader!=null) EB6X Yr
{ <Z\{ijfvD
if(sHeader.equals("Content-Length")) .MID)PY-
{ c6y>]8_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,dVJAV7v
break; /FC(d5I
} 8HHR
} 7KJ0>0~Et
else ={;+0Wjb8
break; m}S}fH(
} YD{N)v
} ?{5}3abB`
catch(IOException e){e.printStackTrace ();} X|QokAR{$>
catch(Exception e){e.printStackTrace ();} .])X.7@x
Vo%Z|
c%(Ndi
Utility.log(nFileLength); R|``A5zQ
A..`?oGj
!,]c}Y{i
return nFileLength; =^_a2_BBl
} G2+ gEg
$M+'jjnP
u`Y~r<?P(
//保存下载信息（文件指针位置） d\tY-X3
private void write_nPos() FV,aQ#
{ k`5K&
try{ )|AxQPd
output = new DataOutputStream(new FileOutputStream(tmpFile)); SZ7; } r8
output.writeInt(nStartPos.length); K@ &;f(Y
for(int i=0;i<nStartPos.length;i++) ASr@5uFR
{ AN|f:259
// output.writeLong(nPos); %L wq.
output.writeLong(fileSplitterFetch.nStartPos); %Y5F@=>&
output.writeLong(fileSplitterFetch.nEndPos); 3f~znO
} 2iOYC0`!
output.close(); ]D=fvvST
} tDfHO1pS
catch(IOException e){e.printStackTrace ();} 475g-t2"@
catch(Exception e){e.printStackTrace ();} #JXXq%4 @
} UN:qE oS
{K?e6-N(z
>J)4e~9EJ2
//读取保存的下载信息（文件指针位置） qElPYN*wF
private void read_nPos() vL^ +X`.td
{ y=[{:
try{ `>)pqI%L[g
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !;hp
int nCount = input.readInt(); i'^! SEt
nStartPos = new long[nCount]; _sy]k A
nEndPos = new long[nCount]; up0=Y o@
for(int i=0;i<nStartPos.length;i++) >g@@ yR,
{ >B*zzj
nStartPos = input.readLong(); ~,xso0
nEndPos = input.readLong(); O'3/21)|y
} 0($On`#
input.close(); 6E^9>
} }m7$,'C%P
catch(IOException e){e.printStackTrace ();} )ZFc5m^+u
catch(Exception e){e.printStackTrace ();} TqOH(={
} =En1?3?
,Tk53"
zqZ/z>Gf
private void processErrorCode(int nErrorCode) NmF8BmIj
{ 2 &_>2"=<@
System.err.println("Error Code : " + nErrorCode); &fU48n1Uh
} NS*Lv
YQD/vc~8G
~@[<y1g?nG
//停止文件下载 @l5GBsLK
public void siteStop() 9jNh%raG|
{ \b$Y_
bStop = true; GJHJ?^%
for(int i=0;i<nStartPos.length;i++) f;Ijl0d@
fileSplitterFetch.splitterStop(); YRd`G3J
>RpMw!NT
yMD0Tj5ZQ
} /V#?d
} +V[;DOlll
//负责部分文件的抓取 -pQ?ybQ
**FileSplitterFetch.java -C!m#"PDW
*/ giW9b_
package NetFox; I }8b]
1\)lD(J\C
g@Y]$ey%A
import java.io.*; kVG+Wr7l0F
import java.net.*; K*4ib/'E a
t'.:"H8BI
yw89*:A6
public class FileSplitterFetch extends Thread { [8oX[oP
Dqd2e&a\
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String sURL; //File URL %5@> nC?`[
long nStartPos; //File Snippet Start Position Z$6B}cz<
long nEndPos; //File Snippet End Position ];N/KHeZ
int nThreadID; //Thread's ID PpF`0w=1%l
boolean bDownOver = false; //Downing is over |)*!&\Ch
boolean bStop = false; //Stop identical jJ,y+o
FileAccessI fileAccessI = null; //File Access interface ,wv>G]v
9JJ6$cLF
s%6L94\t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C^,J6;'
{ x;LO{S4Z
this.sURL = sURL; b5f+q:?{
this.nStartPos = nStart; -mLu!32I<
this.nEndPos = nEnd; roe_H>
nThreadID = id; <yvo<R^30
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B[+b%a3
} u^WZsW
_x,(576~
/ZH*t\
public void run() NJOV!\k
{ 8E9k7
while(nStartPos < nEndPos && !bStop) CoWT
{ &SPr#OkW
4E1j0ARQQ
T eu.i
try{ iQLP~Z>,T
URL url = new URL(sURL); dP]Z:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); K5??WB63B
httpConnection.setRequestProperty("User-Agent","NetFox"); Kq+vAp).
String sProperty = "bytes="+nStartPos+"-"; lE8_Q*ev
httpConnection.setRequestProperty("RANGE",sProperty); Vf=,@7
Utility.log(sProperty); 7vI ROK~
QXEZ?gx
6wXy;!2
InputStream input = httpConnection.getInputStream(); X?/32~\
//logResponseHead(httpConnection); _.%g'=14f
n3 Rf:j^R
lh!8u<yv*
byte[] b = new byte[1024]; [TxvZq*4
int nRead; .SSPJY(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HL:w*8a
{ V!e*J,g
nStartPos += fileAccessI.write(b,0,nRead); #$!^1yO
//if(nThreadID == 1) ?g0dr?H
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u^x<xw6f
} Qp2~ `hD
m"AyO"}I5
=CCddLO
Utility.log("Thread " + nThreadID + " is over!"); mJH4M9WJ]
bDownOver = true; [[]NnWJ
//nPos = fileAccessI.write (b,0,nRead); + EKp*Vje
} LJt5?zQKrW
catch(Exception e){e.printStackTrace ();} ,">CPl]
} }wEt=zOJ
} 0G+qF96
r'XWt]B+[
T?`Ha\go
//打印回应的头信息 zn|O)"C
public void logResponseHead(HttpURLConnection con) vB5mOXGNq
{ [?g}<fa
for(int i=1;;i++) pK/RkA1
{ yWr&G@>G
String header=con.getHeaderFieldKey(i); r"\<+$ 7
if(header!=null) GW%!?mJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *GdJ<B$
Utility.log(header+" : "+con.getHeaderField(header)); %0 U@k!lP
else 3jto$_3'w
break; FR]uCH
} <Oy2JjY
} aghlYcPg
y'JJ#7O=
zhyf}Ta'
public void splitterStop() xr!A>q+@i
{ ~i>'3j0@k
bStop = true; |]-~yYqP3
} eQqCRXx
VjZb\ d4
#ZHKq7
} 6r[pOl:
e%0IEX
cwQ*P$n
/* 6QPT
**FileAccess.java B>cx[.#!
*//文件访问(定位，写) \D#+0
package NetFox; xq%BR[1
import java.io.*; IQmlmu
ktTP~7UVi
NLL"~
public class FileAccessI implements Serializable{ 23^>#b7st
U; oXX
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~bb6NP;'L
RandomAccessFile oSavedFile; P5_Ajb(@'
long nPos; { %X2K
lF!PiL
vNs%e/~vj
public FileAccessI() throws IOException <<MpeMi
{ gp`@dn';
this("",0); ;(`bP
} xE<H@@w
~-7/9$ay5
Ex p?x
public FileAccessI(String sName,long nPos) throws IOException {\1bWr8!U
{ hTn"/|_SW
oSavedFile = new RandomAccessFile(sName,"rw"); jerU[3
this.nPos = nPos; Y%"$v0D
oSavedFile.seek(nPos); bOr11?
} a`w=0]1&*
>EJ{ *
KUZi3\p9W>
public synchronized int write(byte[] b,int nStart,int nLen) wCLniCt
{ )Ac,F6w
int n = -1; +S(# 7
try{ 3/n?g7B
oSavedFile.write(b,nStart,nLen); ?Xypn#OPt
n = nLen; Y`ip.Nx
} Bzwll
catch(IOException e) /C!~v!;e
{ kb2C9<
e.printStackTrace (); F-|DZ?)k5
} u9S*2'
}=bzUA`C
Ly2,*\7
return n; Y0,{fw<
} 1sj7]G]`k
*b) (-#w3
l.pxDMY
} 9abUh3
a[~[lk=7
GCN-T1HvA2
/* Vp]7n!g4l
**SiteInfoBean.java j? BL8E'
*/ Q*#Lr4cm{
package NetFox; ON\bD?(VY
$EFS_*<X
i;%G Z8
public class SiteInfoBean { !I?C8)
2: gh q
-"nkC
private String sSiteURL; //Site's URL M8WjqTq
private String sFilePath; //Saved File's Path RG45S0Ygj
private String sFileName; //Saved File's Name lF(v<drkB
private int nSplitter; //Count of Splited Downloading File j67a?0<C2U
9y6u&!PZ\
LD[\eJ_
public SiteInfoBean() GW>F:<p
{//nSplitter的缺省值为5 GqCBD-@4v.
//default value of nSplitter is 5 tjtvO@?1-
this("","","",5); d {U%q d
} +&G(AW
|"LHo H
6NV592
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) s7 nl
{ G]aey>)
sSiteURL= sURL; ~Re4zU
sFilePath = sPath; O.Pp*sQ^
sFileName = sName; ++,I`x+p
this.nSplitter = nSpiltter; A` _dj}UF
}>@SyE'Q
4Y59^
} g$GGo[_0
:} =lE"2
[x{$f7CEh
public String getSSiteURL() SV t~pE+Y
{ PzKTEYJL
return sSiteURL; u|IS7>Sm
} =p.avAuSn
FA-cTF[,(
WZ?>F
public void setSSiteURL(String value) kfas4mkc
{ *.nSv@F
sSiteURL = value; HQ"T>xb
} 'm*W<
pl r@
Gz{%Z$A~o
public String getSFilePath() kB@gy}
{ Lm}.+.O~d
return sFilePath; ?=Ceo#Er
} -b!Z(}JK
^)]U5+g?
F,S)P`?
public void setSFilePath(String value) u=nd7:bv
{ K.QSt
sFilePath = value; M2cGr
} Ti)Me-g
5?H8?~&dz
z#&1>
public String getSFileName() 9cB+x`+Lu
{ 9oc_*V0<
return sFileName; If'2 m_
} L3\#ufytb
ZbT$f^o}M]
*yT>
public void setSFileName(String value) h'em?fN(
{ ')q4d0B`"
sFileName = value; JqO1 a?H
} J(}PvkA
\VhG'd3k
|qe;+)0>K
public int getNSplitter() _(g0$vRP~
{ ~-vCY
return nSplitter; ,(q] $eOZ
} grE(8M
0#TL$?=|
sTP\}
public void setNSplitter(int nCount) 8?LT*>!
{ 2Pm}wD^`
nSplitter = nCount; TsT5BC63
} kF^4kCJ@
} pqO0M]}
h%F.h![*
9l~D}5e7
/* r}qDvC D
**Utility.java py\:u5QS
*/ Qqg.z-G%.
package NetFox; (y; 6H
stK}K-=`
0'6ai=W
public class Utility { v@QnS
9NwUXh(:(
`l'T/F\
public Utility() `PAQv+EYz
{ jC[_uG
Q(-&}cY
8>WA5:]v
} 5QK%BiDlr
J/P[9m30[
//线程睡眠 "|I.j)
public static void sleep(int nSecond) $=diG
{ hO[_ _j8
try{ XgX~K:<jt
Thread.sleep(nSecond); rkji#\_-FV
} "XxmiK
catch(Exception e) ^cNuEF9
{ rM.Pc?Z
e.printStackTrace (); _fZec+oM
} @4UX~=:686
} A^FkU
hNh!H<}|m8
//日志 D+:s{IcL<
public static void log(String sMsg) nuWQ3w p[e
{ VK*_pEV,}
System.err.println(sMsg); @P~%4:!Hr
} ?&9=f\/P
*K_8=TIA*
0IqGy}+VU
public static void log(int sMsg) d6*84'|!
{ >6yQuB
System.err.println(sMsg); ^G`6Zg;
} l4i51S"
} GdUsv
<QvVPE}z
RuYIG?J=/
/* 67&IaDts
**TestMethod.java X<IW5*
*/ oS$7k3s fj
package NetFox; 40MKf/9
'.z7)n
@2. :fK
public class TestMethod { r ezp7
&&l ZUR,`
*cM=>3ws/
public TestMethod() {1Cnrjw
{ ///xx/weblogic60b2_win.exe 75p9_)>96
try{ _!zc <&~I
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +`wr{kB$~
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UfPB-EFl$D
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7/a7p(
fileFetch.start(); >b"@{MZ@t
} ,N:^4A
catch(Exception e){e.printStackTrace ();} ,w6?Ap
X@[5nyILf
iCpm^XT
} X7OU=+g
y _apT<P
lHM} E$5
public static void main(String[] args) 0~ nCT&V
{ Z<>gx m<
new TestMethod(); 7r?,wM
} Y>aVnixx<
} U/{t"e
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