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)); /"<o""<]
} ${F]N }
for(int i=0;i<nEndPos.length-1;i++) \.<V~d?
{ ]1 OZY@
nEndPos = nStartPos[i+1]; Xm2p<Xu8h
} AR-&c 3o
nEndPos[nEndPos.length-1] = nFileLength; Q7$K,7flf;
} 7R=cxD&
} ?R}a,k
eD481r
_*O^|QbM
//启动子线程 g0D(:_QXp:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; zLxO\R!d
for(int i=0;i<nStartPos.length;i++) @dzO{)
{ RMx$]wn_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !5P\5WF~Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (ft8,^=4
nStartPos,nEndPos,i); p=65L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); gz?]]-H
fileSplitterFetch.start(); 6:(*u{
} Q~A25Jf.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Wb/q&o
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <QyJJQM
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &K_"5.7-56
nEndPos = " + nFileLength); c.u$NnDU6
// fileSplitterFetch[nPos.length-1].start(); ^$7Lmd.qI
XJ|CC.]1u
0P<bS?e<l
//等待子线程结束 /^kZ}}9baU
//int count = 0; L`$MOdF{_
//是否结束while循环 e.<$G'
boolean breakWhile = false; h$Z_r($b
]e'Ol$3U9=
5m`@ 4%)zp
while(!bStop) yu'2
{ a+TlZE>8
write_nPos(); 3JiJ,<,7
Utility.sleep(500); 9nFPGIz+
breakWhile = true; J2BW>T!tuw
meHAa`
o!`.LL%
for(int i=0;i<nStartPos.length;i++) (=d%Bn$6b
{ 5JE8/CbH
if(!fileSplitterFetch.bDownOver) L {6y]t7^
{ $q]:m+Fm
breakWhile = false; >;N0( xB
break; ;~Ke5os=s
} (%huWW j
} d~](S<k
if(breakWhile) 7-"ml\z
break; )&"l3*x
:*aBiX"
@;iW)a_M
//count++; ]VifDFL}
//if(count>4) ^mLZT*
// siteStop(); t{\FV@R
} Iz/o|o]#
VjbRjn5LI
X6jW mo8]
System.err.println("文件下载结束！"); lHBk&UN'
} #>+O=YO
catch(Exception e){e.printStackTrace ();} q<L>r?T[
} :yN;_bC!b%
\$Xo5f<
$=7[.z&
//获得文件长度 &>UI{
public long getFileSize() acgtXfHR
{ c <8s\2
int nFileLength = -1; &?m|PK)I
try{ _T6l*D
URL url = new URL(siteInfoBean.getSSiteURL()); 6/ir("LK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d'~ kf#
httpConnection.setRequestProperty("User-Agent","NetFox"); pp$WM\r
byl#8=?
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int responseCode=httpConnection.getResponseCode(); \2(Uqf#_
if(responseCode>=400) L~_3BX
{ *NdSL
processErrorCode(responseCode); V)M+dhl
return -2; //-2 represent access is error E5D5
} 413,O~^
~1&%,$fZ
!|hxr#q=4
String sHeader; iR;Sd >)
<aJdm!6
b/IT8Cm3
for(int i=1;;i++) SoZ$1$o2
{ tsdkpt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uK6`3lCD
//Utility.log(in.readLine()); BdcTKC
sHeader=httpConnection.getHeaderFieldKey(i); QXZjsa_|
if(sHeader!=null) ?N2/;u>
{ 4fPbwiKj
if(sHeader.equals("Content-Length")) 1&A@Zo5|
{ T 9Jv
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +L_!$"I
break; '\qd{mM\r
} &z[39Q{~
} =Nn&$h l
else bF:]MB^VK
break; #L[-WC]1y
} o@TxDG
} M`!\$D
catch(IOException e){e.printStackTrace ();} g_?:G$1H
catch(Exception e){e.printStackTrace ();} p!^.;c
40cgsRa|
<Z%iP{
Utility.log(nFileLength); ]Igd<
\a]JH\T)Q
J [}8&sn
return nFileLength; "Ka2jw,
} xBH`=e<
6x%uWZa'
:#8#tLv
//保存下载信息（文件指针位置） ({=: N
private void write_nPos() [iE%P^
{ ^c?2n
try{ D<9FSxl6
output = new DataOutputStream(new FileOutputStream(tmpFile)); X;JptF^
output.writeInt(nStartPos.length); W=YFe<Q
for(int i=0;i<nStartPos.length;i++) S;DqM;Q
{ jbx@ty
// output.writeLong(nPos); # Vz9j
output.writeLong(fileSplitterFetch.nStartPos); M&P?/Zi=L
output.writeLong(fileSplitterFetch.nEndPos); @QiuCB
} vt0XCUnK
output.close(); +*"u(7AV
} >r+Dl\R
catch(IOException e){e.printStackTrace ();} g.-{=kZ
catch(Exception e){e.printStackTrace ();} S;#S3?G
} H^ _[IkuA%
JR/:XYS+
((i%h^tGa;
//读取保存的下载信息（文件指针位置） 8>" vAEf
private void read_nPos() n}?XFx!%
{ ,Bh!|H(?L1
try{ c@d[HstBJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .&O}/B
int nCount = input.readInt(); 61e)SIRz9I
nStartPos = new long[nCount]; u0M[B7Q
nEndPos = new long[nCount]; w"Gci~]bXU
for(int i=0;i<nStartPos.length;i++) vR$[#`X
{ uan%j]|q%
nStartPos = input.readLong(); 1}1.5[4d
nEndPos = input.readLong(); &2-dZK
} wZ7Opm<nt
input.close(); GSzb
} -xg$qvK
catch(IOException e){e.printStackTrace ();} D:`b61sWi_
catch(Exception e){e.printStackTrace ();} o^P/ -&T
} ? <b>2j
@=CN#D12
Pn:L=*
private void processErrorCode(int nErrorCode) #-S%aeB
{ d:08@~#
System.err.println("Error Code : " + nErrorCode); s;!TB6b@
} R42+^'af
v@_}R_pX
A")F7F31c
//停止文件下载 .Jk[thyU
public void siteStop() gaFOm9y.e
{ #{-l(016y
bStop = true; 1/b5i8I2v
for(int i=0;i<nStartPos.length;i++) Ph@hk0dgr/
fileSplitterFetch.splitterStop(); CK4C:`YG
+<#0V!DM
X2CpA;#;7l
} ~mAv)JK
} vjNP
//负责部分文件的抓取 jz CA2N%
**FileSplitterFetch.java 4%k{vo5i
*/ }N@8zB~X
package NetFox; AlZ]UGf^
fpd4 v|(
a=m4)tjk
import java.io.*; ?T.' q
import java.net.*; %x(||cq
p'SclH[
{yXpBS
public class FileSplitterFetch extends Thread { +5AWX,9,-
D==C"}J
mdzUL d5J
String sURL; //File URL gJ \CT'/
long nStartPos; //File Snippet Start Position V)|]w[(Y
long nEndPos; //File Snippet End Position c, IAz
int nThreadID; //Thread's ID IR_&dWHyc
boolean bDownOver = false; //Downing is over Whd.AaD\
boolean bStop = false; //Stop identical PBkTI2 v
FileAccessI fileAccessI = null; //File Access interface JU>F&g/|
|aD8
_k'?eZB
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0Y|"Bo9k
{ _+B{n^ {
this.sURL = sURL; l~mC$>f
this.nStartPos = nStart; }\#u~k!l
this.nEndPos = nEnd; &/+LY_r'<I
nThreadID = id; zE,1zBS<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;T-`~
} $kAal26z
W!Qaa(o?
ZovF]jf k
public void run() lE=&hba
{ 7)-uYi] dA
while(nStartPos < nEndPos && !bStop) ~DJILc
{ n{*A<-vL
/#Fz K
c^F@9{I
try{ >;s!X(6b
URL url = new URL(sURL); $cSmubZK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u.yjk/jF
httpConnection.setRequestProperty("User-Agent","NetFox"); I+GP`=\
String sProperty = "bytes="+nStartPos+"-"; +o3 ZQ9
httpConnection.setRequestProperty("RANGE",sProperty); ]broU%#"
Utility.log(sProperty); r]3v.GZy
xofxE4.
yd=NafPM
InputStream input = httpConnection.getInputStream(); {3@"}Eh
//logResponseHead(httpConnection); r?%,#1|$$
!Bu=?gf
7X{@$>+S
byte[] b = new byte[1024]; ;659E_y>
int nRead; M`D`-vv
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) w678
{ Q=u [j|0mc
nStartPos += fileAccessI.write(b,0,nRead); !QsmT3
//if(nThreadID == 1) pY$DOr-r`
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F9J9zs*,
} [M#I Nm}
/P[@o
3kW%,d*_
Utility.log("Thread " + nThreadID + " is over!"); X,`^z,M%I
bDownOver = true; R^VmNj
//nPos = fileAccessI.write (b,0,nRead); 4<btWbk5u*
} m?y'Y`
catch(Exception e){e.printStackTrace ();} K<vb4!9Z9
} fq(3uE]nC
} ekPn`U
W61nJ7@
91oAg[@4G
//打印回应的头信息 >>.4@
public void logResponseHead(HttpURLConnection con) ;~"#aL50fe
{ seS)`@n
for(int i=1;;i++) F3=iyiz6
{ Ou5,7Ne
String header=con.getHeaderFieldKey(i); 'fka?lL
if(header!=null) 5 8n(fdE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 115zvW
Utility.log(header+" : "+con.getHeaderField(header)); Eemk2>iP?
else iu+rg(*%
break; ^laf!kIP
} JN<IMH
} @DK;i_i
0OPpALl
DgRA\[c
public void splitterStop() G8Sx;Xi
{ h0n,WU/Kw
bStop = true; )Qixde>]p
} [;8vO=Z
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@Sd l~'"
} oZ"93]3-
z8\;XR
2[Q/|D}}|
/* /ng+IC3
**FileAccess.java [Csv/
*//文件访问(定位，写) R6/vhze4L2
package NetFox; V=DT.u
import java.io.*; 1E|~;wo\
|"XxM(Dm
{'R\C5:D7
public class FileAccessI implements Serializable{ Lr}>Md
c<n <!!vi
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 <4QOjW
RandomAccessFile oSavedFile; A-XWG9nL
long nPos; @Nk]f
Bm&%N?9
S|HnmkV66
public FileAccessI() throws IOException L4C_qb k;:
{ h,WF'X+
this("",0); b3RCsIz
} 8>y!=+9_
(hv>vfY@
(aa}0r5
public FileAccessI(String sName,long nPos) throws IOException 3(/J(8
{ lqe71](sK8
oSavedFile = new RandomAccessFile(sName,"rw"); j/+e5.EX/
this.nPos = nPos; @p}"B9h*^
oSavedFile.seek(nPos); GDMg.w4Yk
} d:V6.7>,
js#72T/_n
Z(=UZI?
public synchronized int write(byte[] b,int nStart,int nLen) [O52Bn
{ !Hp H
int n = -1; "X7;^yY
try{ KL}o%wfLy
oSavedFile.write(b,nStart,nLen); Im*~6[
n = nLen; <.lT.>'?
} #pvq9fss,}
catch(IOException e) 6KddHyFz
{ D ,kxB~
e.printStackTrace (); r8 9o
} <K CI@
T5:Q_o]
lHM+<Z
return n; p/Pus;*s
} Skr(C5T
r#zcl)rbU
x}/jh
} ;\K]~
$Cz2b/O
|[`YGA4
/* h*Fv~j'p
**SiteInfoBean.java )LGVR3#
*/ :E9pdx+
package NetFox; TAG@Ab
ad}8~6}_&
o;@~uU
public class SiteInfoBean { aM~IRLmK
NK0'\~7&
3t-STk?
private String sSiteURL; //Site's URL 7Fj8Mp|
private String sFilePath; //Saved File's Path 8dR `T}
private String sFileName; //Saved File's Name q/@2=$]hH3
private int nSplitter; //Count of Splited Downloading File lC($@sC%
NtM>`5{?
YE`Y t
public SiteInfoBean() 0OO[@Ht
{//nSplitter的缺省值为5 "qgwuWbM
//default value of nSplitter is 5 jL-2 }XrA
this("","","",5); qur2t8gnxq
} lie,A
,zgz7
,sitOy}ks
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NgTB4I8P
{ +,,(8=5g
sSiteURL= sURL; /4T6Z[=s
sFilePath = sPath; ( v*xW.
sFileName = sName; kWW2N0~$
this.nSplitter = nSpiltter; #LR4%}mg
5Npxs&Ea
&dtst??
} 'I>USl3hI
# Wi?I=,
uH*6@aYPo
public String getSSiteURL() $ 64up!
{ Qyw@ r
return sSiteURL; =mXC,<]
} U~D~C~\2;
q=pRe-{
a <C?- g|
public void setSSiteURL(String value) L2>e@p\>
{ Xqw}O2QQ1
sSiteURL = value; Z3JUYEAS
} qFWN._R
,]EhDW6
X$5
public String getSFilePath() :.5l
{ P<IDb%W
return sFilePath; TVcA%]y{;
} d3:GmB .
l Xa/5QKC
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public void setSFilePath(String value) A1/@KC"&{G
{ US$$ADq
sFilePath = value; P] *x6c^n
} "r46Rfa
>OaD7
Y'iI_cg
public String getSFileName() WGz)-IB!PE
{ by<@\n2B:U
return sFileName; hnFpC1TO
} 8;?4rrS
~1+6gG
GqHW.s5
public void setSFileName(String value) Mw0>p5+ cy
{ Nbr$G=U
sFileName = value; <-k!
} G$f%]A1
dJgLS^1E
e4` L8
public int getNSplitter() #VrIU8Q7'
{ ;(?tlFc
return nSplitter; o{y}c->
} *#YZm>h
qA GjR!=^
D#LV&4e>.E
public void setNSplitter(int nCount) uj6'T Sl
{ ]^C 8Oh<
nSplitter = nCount; bqED5;d'#
} ! $$>D"
} zzZEX
&MSU<S?1
{[2o
/* %[$HX'Y
**Utility.java M,fL(b;2
*/ MOD&3>NI
package NetFox; Zkd{EMW
I&+.IK_
X8*g#lO?
public class Utility { ~`AB-0t.u
$/M-@3wro
[1vm~w'
public Utility() -i8KJzPL f
{ &DMC\R*j
`2 <:$]
-LiGO#U
} ~Y/A]N86,
QH-CZ6M
//线程睡眠 E /H%q|q
public static void sleep(int nSecond) tQ9%rb
{ hH`x*:Qja
try{ nNCR5&,q
Thread.sleep(nSecond); FFqK tj's
} *5PQ>d G
catch(Exception e) } [#8>T
{ hq7f"`
e.printStackTrace (); ]W?cy
} U(f@zGV
} f![] :L
z[f]mU
//日志 %AO6=
public static void log(String sMsg) zls^JTE
{ STnMBz7
System.err.println(sMsg); <~dfp
} "zq'nV=
eF%M2:&c;
:XY%@n
public static void log(int sMsg) KF'fg R
{ R%3yxnM*
System.err.println(sMsg); }K)AjZ
} f$>_>E
} qR.FjQOvn
iOZ9A~Ywy
~+'f[!^
/* h^(U:M=A
**TestMethod.java ]izHn;+
*/ X.#*+k3s0
package NetFox; cgG*7E
Ou1kSG|kM
O + aK#eF
public class TestMethod { C+/EPPi
n*9QSyJN]
l0G{{R0Y
public TestMethod() drAJ-ii
{ ///xx/weblogic60b2_win.exe "S#$:92
try{ Ei:m@}g
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B-LV/WJ_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UhJS=YvT
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0i}.l\
fileFetch.start(); bDDP:INm.
} Vb?wwx7=
catch(Exception e){e.printStackTrace ();} /HUT6B
2(!W 9#]
fP<==DK
} }N9PV/a
J <z ^C
c<Ud[x.
public static void main(String[] args) '19?
{ vwAhNw2-
new TestMethod(); +~1FKLu
} 6xr%xk2E
} -`X`Ff
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