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)); U p: M[S
} Ba;tEF{X
for(int i=0;i<nEndPos.length-1;i++) r1|;V~a$~
{ ~ 6Hi"w
nEndPos = nStartPos[i+1]; ]Hrw$\Ky
} ?uqPye1fc
nEndPos[nEndPos.length-1] = nFileLength; o1u?H4z
} 4G=KyRKh
} :Pi="
IsB=G-s
);ZxKGjc4
//启动子线程 i M!=/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; MH_3nN
for(int i=0;i<nStartPos.length;i++) uJL[m(G
{ Z~DR,:
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }&IOBYHVDo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), rFYw6&;vOi
nStartPos,nEndPos,i); YW^sf,zQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DsGtc<l%
fileSplitterFetch.start(); EY[J;H_b
} R(DlJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $jv/00:&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IHNl`\Le
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1WLaJ%Fv
nEndPos = " + nFileLength); dL>8|
// fileSplitterFetch[nPos.length-1].start(); =^gZJ@
2k"!o~s^
z<n&P7k5j
//等待子线程结束 "TePO7^m
//int count = 0; SFa~j)9'n
//是否结束while循环 g;G.uF&
boolean breakWhile = false; ,$;pLjo6
r WPoR/M
@ykM98K
while(!bStop) I0C$
{ [V.#w|n
write_nPos(); )nA fT0()0
Utility.sleep(500); ^Euqy,8}
breakWhile = true; +`Ypc
OG}m+K&<
($Ck5`_MK
for(int i=0;i<nStartPos.length;i++) y4~;H{!
{ S%k](\7!
if(!fileSplitterFetch.bDownOver) Ce_ES.
{ B&c*KaK;~
breakWhile = false; 44(l1xEN+
break; X2hyxTOp
} uvj`r5ei
} X\'+);Z
if(breakWhile) K,L
break; <GRrw
MLn\b0
:I^I=A%Pe(
//count++; B]|"ePj-
//if(count>4) `f+l\'.s
// siteStop(); e`Vb.E)
} AH#klYK
w-9fskd6e
([L5i&DT
System.err.println("文件下载结束！"); OMVK\_oXo
} UFY_.N~
catch(Exception e){e.printStackTrace ();} 7Q3a0`Iq
} k874tD
.l(t\BfE~
/4PV<[ :_
//获得文件长度 86N"EuH$
public long getFileSize() x7l3&;yDv
{ yUzpl[*e^o
int nFileLength = -1; S,~DA3
try{ RkuPMs Hw;
URL url = new URL(siteInfoBean.getSSiteURL()); U k*HRudt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l d4#jV ei
httpConnection.setRequestProperty("User-Agent","NetFox"); -<Zs7(
l2LUcI$ x
?A7_&=J%
int responseCode=httpConnection.getResponseCode(); dwAFJhgh
if(responseCode>=400) N++jI(
{ P(#by{s
processErrorCode(responseCode); 7Ta",S@m
return -2; //-2 represent access is error m?Qr)F_M
} 3>t^Xu~
ME%W,B.|"s
;.4A,7w#
String sHeader; (( D*kd"
o:irwfArv
,3tcti~sZ
for(int i=1;;i++) A$]&j5nh|
{ \$] V#@F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,Bg)p_B
//Utility.log(in.readLine()); qFD#D_O6
sHeader=httpConnection.getHeaderFieldKey(i); kxp, ZP
if(sHeader!=null) ZW0gd7Wh
{ *.]M1
if(sHeader.equals("Content-Length")) b7_uT`<
{ ToWtltCD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $<(FZb=
break; Zw`vPvb!
} ;>duY\$<
} !$i*u-%4
else <p74U( V
break; !K~:crUV|S
} tuF hPqe {
} %@jL?u
catch(IOException e){e.printStackTrace ();} `Z:5E
catch(Exception e){e.printStackTrace ();} <cn{S`
b=Y:`&o=[
~:\QC
Utility.log(nFileLength); dE[nPtstb
&eHhj9
W%xg;uzp
return nFileLength; I*Q^$YnM
} N5%zbfKM
9j;L-
~;*SW[4
//保存下载信息（文件指针位置） SXW8p>1Jw
private void write_nPos() (!@ Q\P
{ :DlgNR`bq
try{ t<|S7EqIL
output = new DataOutputStream(new FileOutputStream(tmpFile)); &(]@L\A
output.writeInt(nStartPos.length); 1dy>a=W
for(int i=0;i<nStartPos.length;i++) z!r-g(^G
{ g5 J[ut
// output.writeLong(nPos); z"@yE*6
output.writeLong(fileSplitterFetch.nStartPos); IP]"D"
output.writeLong(fileSplitterFetch.nEndPos); [8o!X)
} 5D32d1A
output.close(); Wp[R$/uT
} ` 5.PPI\h2
catch(IOException e){e.printStackTrace ();} UE[5Bw?4X
catch(Exception e){e.printStackTrace ();} qx$-% P
} k9ThWo/#u
0~5'O[NhF
?x|8"*N
//读取保存的下载信息（文件指针位置） EN =oA P
private void read_nPos() 0=2D90
{ v;q<h
try{ 8Q%rBl.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q-g3!
int nCount = input.readInt(); LXIQpD,M
nStartPos = new long[nCount]; %$)[qa3
nEndPos = new long[nCount]; 4nfpPNt
for(int i=0;i<nStartPos.length;i++) fJb<<6C
{ 'ow`ej
nStartPos = input.readLong(); i9qn_/<c
nEndPos = input.readLong(); =2 3H/
} nnV(MB4z1
input.close(); @C]Q;>^|
} }w0>mA0=H
catch(IOException e){e.printStackTrace ();} F3aOKV^
catch(Exception e){e.printStackTrace ();} :+9KNyA
} f#s /Ycp+
iG\]
$\0%"S
private void processErrorCode(int nErrorCode) :3z`+5Y*
{ {c'2{`px 5
System.err.println("Error Code : " + nErrorCode); 6[dLj9 G%
} F ;o ^.
k}5Sz
SIBNU3;DL
//停止文件下载 oJcDs-!
public void siteStop() : "|M
{ V'XmMn)!
bStop = true; I.f)rMl+h
for(int i=0;i<nStartPos.length;i++) +J^-B}v
fileSplitterFetch.splitterStop(); z$VA]tI(
yEnurq%J
5Iv3B|u
} 2{v$GFc/
} 1keH1[
//负责部分文件的抓取 FCC9Ht8U?
**FileSplitterFetch.java }/ p>DMN
*/ 9t.u9C=!F
package NetFox; QJL%J
DS@ZE Q`F
lG\6z"K
import java.io.*; tSr.0'CE
import java.net.*; /'V(F* g
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HC4vet
public class FileSplitterFetch extends Thread { "k)}qI{
Osb#<9{}
"ooq1 0P
String sURL; //File URL U>bmCK2
long nStartPos; //File Snippet Start Position )575JY `6K
long nEndPos; //File Snippet End Position i?.7o*w8
int nThreadID; //Thread's ID 8X6F6RK6,1
boolean bDownOver = false; //Downing is over CCCd=s.
boolean bStop = false; //Stop identical W6_~.m"b
FileAccessI fileAccessI = null; //File Access interface 0Q81$% @<
XYJ7k7zc+Y
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C%$:Oq
{ 7oPLO(0L
this.sURL = sURL; Y#>'.$(Az
this.nStartPos = nStart; C@{#OOa
this.nEndPos = nEnd; |i)7jG<
nThreadID = id; hL1q9%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cs]N%M^s
} OF$0]V
[Yo3=(7J
w4m-DR5
public void run() 3{gD'y4j
{ *SW.K{{
while(nStartPos < nEndPos && !bStop) ?-40bb
{ |\yVnk!c
V Ae@P
q .[hwm
try{ %^e~;i=2
URL url = new URL(sURL); [0M2`x4`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O~E6"vQ
httpConnection.setRequestProperty("User-Agent","NetFox"); [D8u.8q
String sProperty = "bytes="+nStartPos+"-"; Q}pnb3J>T
httpConnection.setRequestProperty("RANGE",sProperty); ' }G!D
Utility.log(sProperty); ^hG Y,\K9
_0~WT
]}KoW?M
InputStream input = httpConnection.getInputStream(); <r6e23
//logResponseHead(httpConnection); av-l_iE
{s=n "*Qp)
(zW;&A
byte[] b = new byte[1024]; E5-f{Qc
int nRead; dQ&S&SW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @8IYJ{=
{ .AEOf0t
nStartPos += fileAccessI.write(b,0,nRead); ZG=B'4W
//if(nThreadID == 1) 'S_kD! BO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wz!a;]agg
} ^tWt"GgC
-8sm^A>C
u/`jb2eEU:
Utility.log("Thread " + nThreadID + " is over!"); I) mP?
bDownOver = true; ~i`@
//nPos = fileAccessI.write (b,0,nRead); W<J".2D
} [x`trypg
catch(Exception e){e.printStackTrace ();} r?{$k3Vl
} KmuE#Ia
} @,Je*5$o"
d>ltL`xn
WM& k
//打印回应的头信息 x?hdC)#DWI
public void logResponseHead(HttpURLConnection con) gv&%2e}_
{ jy=dB-&
for(int i=1;;i++) #[.vfG
{ |K},f,
String header=con.getHeaderFieldKey(i); F-!,U)
if(header!=null) 8.Q;o+NU
//responseHeaders.put(header,httpConnection.getHeaderField(header)); E0K'|*
Utility.log(header+" : "+con.getHeaderField(header)); s|7(VUPL
else 'r KDw06/
break; em^|E73
} %O5 k+~9
} LnQm2uF
]X:{y&g(
UlBg6
public void splitterStop() nC^|83
{ a );>
bStop = true; EJ$-
} `v*UY
.&:GOD
GA19=gow
} bM]\mo>z<
N3P!<J/tc
[4)q6N5`f
/* gTz66a@i
**FileAccess.java &!I^m
*//文件访问(定位，写) xkv2#"*v
package NetFox; wJ_E\vP
import java.io.*; )9~1XiS,
OrXx0Hn
"%O,*t
public class FileAccessI implements Serializable{ 7aH E:Dnwp
liEb(<$a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 DlB"o.
RandomAccessFile oSavedFile; hZ0p /Bdv
long nPos; FA 1E`AdU
LOY+^
SK2nxZOH
public FileAccessI() throws IOException qXPT1%+)y
{ \cq gCab/2
this("",0); neQ2k=ao
} z7+y{-{Z
5t6!K?}
b .9]b
public FileAccessI(String sName,long nPos) throws IOException ;6N@raP7
{ S>~QuCMY
oSavedFile = new RandomAccessFile(sName,"rw"); qzv$E;zAl
this.nPos = nPos; uq;,h46ki
oSavedFile.seek(nPos); <y${Pkrj
} OtuOT=%
0mB]*<x8
6l|pTyb1
public synchronized int write(byte[] b,int nStart,int nLen) ajy.K'B*
{ -#]?3*NO
int n = -1; pm<zw-
try{ Lu&2^USTO
oSavedFile.write(b,nStart,nLen); O@U[S.IK
n = nLen; ;^)(q<]
} k[oU}~*U+
catch(IOException e) YH`/;H=$G/
{ Ba/Z<1)
e.printStackTrace (); n50XGv
} ZOl =zn
v#/Uq?us
&_ er_V~
return n; ehO@3%z30c
} \nV|Y=5
'tK5s>gv<
X<s']C9c
} gx&BzODPd0
=Haqr*PDx
2Mx9Kd'a r
/* Sc "J5^
**SiteInfoBean.java =p>"PqJ/7n
*/ "m3:HS
package NetFox; >'eOzMBn
\ief [
Z~o*$tF/
public class SiteInfoBean { Fz7(Kuc
b7>^w<ki
WAiEINQ^)
private String sSiteURL; //Site's URL JsOPI]
private String sFilePath; //Saved File's Path +F ~;Q$T
private String sFileName; //Saved File's Name ,-Fhb~u
private int nSplitter; //Count of Splited Downloading File "iE9X.6NMu
D"fE )@Q@Y
s}A)sBsaP3
public SiteInfoBean() GqhnE>
{//nSplitter的缺省值为5 j.4oYxK!s/
//default value of nSplitter is 5 +=%13cA*U
this("","","",5); P%>? O :a
} pmXx2T#=
B+|E|8"
BM{GSX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i%H_ua
{ CtVY;eG
sSiteURL= sURL; 9BB<. p
sFilePath = sPath; 3ydOBeY
sFileName = sName; ^[XxE Lx
this.nSplitter = nSpiltter; OxX{[|!`
u3kK!2cdP
IjN3 jU
} \Q{@AC<?i
:7p0JGd
!cw<C*
public String getSSiteURL() 0Mt2Rg}
{ B{!)GZ(}
return sSiteURL; NAhV8
} ed*Cx~rT
'nI2RX
!*u5HVn
public void setSSiteURL(String value) @lAOi1m,,
{ b].:2
sSiteURL = value; H[V^wyi'z
} hNc;,13
i0,{*LD%^
?ECmPS1
public String getSFilePath() T^NY|Y/
{ ,5'LbO-
return sFilePath; 8rXq-V_u
} &/R@cS6}'
C.s{&
@/yRE^c
public void setSFilePath(String value) (?xGlV`n
{ qf+jfc(Iby
sFilePath = value; %([$v6y
} OYC4iI
JU:!lyd
WKX5Dl
public String getSFileName() cO<]%L0
{ 57IrD*{
return sFileName; b$[_(QUw
} (.P;VH9R\
y&9S+
_)2.#L
public void setSFileName(String value) zc]F
{ O/gok+K
sFileName = value; QL}5vSl
} Yqmx]7Y4
#NNj#
>joGGT
public int getNSplitter() O;f^'N
{ 4C[,S|J
return nSplitter; fOJk+? c
} Rp A76ug
Nv*x^y]
>OE.6)'Rm
public void setNSplitter(int nCount) [Z,AquCU(
{ u_@%}zo?5*
nSplitter = nCount; yk#yrxM
} qyUcjc%[
} p*!@z|F>U
YS?P A#
NmST1pMk
/* = Ii@-C
**Utility.java i2.y)K)
*/ Zqd&EOm
package NetFox; ,Ng3!2&$e
K%qunjv
{d}-SoxH
public class Utility { I"Ji_4QV
/`hr)
' F`*(\#
public Utility() s6Bt)8A
{ NUH;GMj,,
p1v:X?
0-0 )E&2
} #"ayq,GC<
|/arxb&
//线程睡眠 aen(Mcd3bg
public static void sleep(int nSecond) nX5*pTfjL3
{ &Xe r#6~
try{ tA#X@HIE
Thread.sleep(nSecond); p$f#W
} (J.(Fl>^
catch(Exception e) KwPJ0 ]('_
{ =t@m:
e.printStackTrace (); ~0ZEnejy
} D\(,:_ge
} h|=^@F_\`
\*LMc69
//日志 n8[sR;r5f
public static void log(String sMsg) |rdG+>
{ &-<"HW
System.err.println(sMsg); wuzz Wq
} }K~JM1(26
KblOP{I
kjaz{&P
public static void log(int sMsg) n#z^uq|v
{ |GK [I
System.err.println(sMsg); {N)\It
} :1_hQeq
} =e$ #m;
zIF &ZYP
[w=x0J&
/* bQXxb(^
**TestMethod.java 6$ IXER
*/ t vk^L3=<
package NetFox; JsnavI6
bIp;$ZHy`K
`6~*kCj5
public class TestMethod { yel>-=Vn
CSr{MF`]e
(ZShhy8g
public TestMethod() pal))e!B
{ ///xx/weblogic60b2_win.exe FVY,CeA.
try{ WU<#_by g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <$?:|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $k'f)E
SiteFileFetch fileFetch = new SiteFileFetch(bean); 3Xd+>'H
fileFetch.start(); NnHwk)'
} R%#c~NOO
catch(Exception e){e.printStackTrace ();} iM8hGQ`
DIk$9$"<x
ljiq+tT
} ^]U2Jd
bx6@FKns}
7[D0n7B@
public static void main(String[] args) C{!Czz.N
{ *D AgcB
new TestMethod(); S BFhC
} Y\+^\`Tqu
} _ <>+Dk&
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