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)); RJrz ~,}
} TR"C<&y$j
for(int i=0;i<nEndPos.length-1;i++) 3[YG BM(
{ v, $r.g;
nEndPos = nStartPos[i+1]; t un}rdb
} Ot=jwvw
nEndPos[nEndPos.length-1] = nFileLength; lSj gN~:z
} 7aG.?Ca%
} "s2_X+4oY
OxlA)$.hpu
;FPx
//启动子线程 Pf*6/7S:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2;}leZ@U
for(int i=0;i<nStartPos.length;i++) ^|Ap_!t$;
{ p@<Q?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &OMlW_FHR
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), V>@[\N[
nStartPos,nEndPos,i); o-,."|6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YB#fAU
fileSplitterFetch.start(); =$>=EBH,cm
} `+7F H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 615Ya<3f8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,6)N.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ks405
nEndPos = " + nFileLength); xEb>6+-F@
// fileSplitterFetch[nPos.length-1].start(); #8$?# dT
Y"Cf84E
ZlT }cA/n
//等待子线程结束 pu-HEv}]a|
//int count = 0; eV;r /4
//是否结束while循环 _:x]'w%
boolean breakWhile = false; 9^gYy&+>6]
E C?}iP
Ss3p6%V/
while(!bStop) ^QK`z@B
{ twT/uBQ4a
write_nPos(); }0'=}BE
Utility.sleep(500); 3]Z1kB
breakWhile = true; u?osX;'w
L\:|95Yq
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for(int i=0;i<nStartPos.length;i++) 'o AmA=
{ TOwd+]B
if(!fileSplitterFetch.bDownOver) UhxM85M;x
{ MK&,2>m,A
breakWhile = false; TCr4-"`r-{
break; ^Hd[+vAvR
} ( }-*irSsj
} HiCh:IP7>/
if(breakWhile) _&<n'fK[
break; 5mH[|_
GO"`{|o
7v: XAU
//count++; Y.^L^ "%dF
//if(count>4) p|>*M\LE#
// siteStop(); +8Xjk\Hi
} /K=OsMl2b8
u4x-GObJM
S{c/3k~
System.err.println("文件下载结束！"); *a9cBl'_
} 'Wlbh:=$
catch(Exception e){e.printStackTrace ();} bJd|mm/v
} =i/Df?
{)YbksrJ{
v"*r %nCi
//获得文件长度 J_Lmy7~xbD
public long getFileSize() O-?rFNavxp
{ IH|zNg{\Y
int nFileLength = -1; qmS9*me {
try{ mF4W4~"
URL url = new URL(siteInfoBean.getSSiteURL()); 5ggyk0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qu=~\t1[6
httpConnection.setRequestProperty("User-Agent","NetFox"); Jo?LPR \6
^q7V%{54
2Q^q$@L
int responseCode=httpConnection.getResponseCode(); ~_THvx1
if(responseCode>=400) M2$/x`\-~
{ u$ts>Q;5
processErrorCode(responseCode); )aS:h}zn
return -2; //-2 represent access is error Q*DT" W/0
} m\:^9A4HCg
MZgaQUg
YteIp'T
String sHeader; bnxp[Qk|5
1p&.\^
9~SPoR/_0
for(int i=1;;i++) _O`prX.:B0
{ eG=d)`.JaV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); P,v7twc0M
//Utility.log(in.readLine()); 5Xq+lLW>
sHeader=httpConnection.getHeaderFieldKey(i); 2/-m-5A
if(sHeader!=null) ($di]lbsT
{ corm'AJ/
if(sHeader.equals("Content-Length")) |J$A%27
{ A95f!a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Xdvd\H=
break; ;jPsS^X
} E-A9lJWr
} Gp9 <LB\,
else HQ-[k$d W4
break; wL;OQhI
} lrrTeE*
} *G"hjc$L
catch(IOException e){e.printStackTrace ();} di\.*7l?
catch(Exception e){e.printStackTrace ();} }7PJr/IuF
5'!fi]Z
1+%UZK= K
Utility.log(nFileLength); D*l(p5[
y?sz&*:
ak7%
return nFileLength; \XDiw~0
} \f,<\mJ#
?1Nz ,Lc$
kQ\GVI11?
//保存下载信息（文件指针位置） <spG]Xa<
private void write_nPos() x[A|@\Z
{ 757&bH|a
try{ +17!v_4^
output = new DataOutputStream(new FileOutputStream(tmpFile)); .Xlo-gHk
output.writeInt(nStartPos.length); yg\QtWWM
for(int i=0;i<nStartPos.length;i++) D+T/ Z)
{ G|cjI*
// output.writeLong(nPos); ,Yag! i>;
output.writeLong(fileSplitterFetch.nStartPos); RDps{),E;d
output.writeLong(fileSplitterFetch.nEndPos); k>i88^kPV
} S|tD8A
output.close(); 3M#x)cW
} "&_+!TBg,
catch(IOException e){e.printStackTrace ();} HT7,B(.}
catch(Exception e){e.printStackTrace ();} 1wgL^Qz@
} v.ZUYa|
GRc)3 2,
L15)+^4n
//读取保存的下载信息（文件指针位置） \`.v8C>vG
private void read_nPos() &r,vD,
{ EU(e5vO
try{ C(>!?-.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [8u9q.IZ
int nCount = input.readInt(); f2.=1)u.
nStartPos = new long[nCount]; 2Z; !N37U
nEndPos = new long[nCount]; "P7OD^(x/
for(int i=0;i<nStartPos.length;i++) 9Og
{ N8]DzE0%
nStartPos = input.readLong(); [I;C6p
nEndPos = input.readLong(); U|wST&rU|
} D#nHg
input.close(); <Zva
} g0f4>m
catch(IOException e){e.printStackTrace ();} VEV?$R7;
catch(Exception e){e.printStackTrace ();} 6AIqoX*p
} y[J9"k(@
5K Ij}VN
(N/u@M
private void processErrorCode(int nErrorCode) BOpZ8p'eH1
{ :ok.[q
System.err.println("Error Code : " + nErrorCode); Y`gO:d8
} Q8m~L1//S
Mg >%EH/'
P`rfDQoZ
//停止文件下载 *,u{,$}2
public void siteStop() >p&"X 2 @
{ &5}YTKe}|
bStop = true; JCH9~n.
for(int i=0;i<nStartPos.length;i++) UV(`.
fileSplitterFetch.splitterStop(); x@X2r
Boj R"
dr)*.<_+a(
} %=z>kU1|
} qt:B]#j@
//负责部分文件的抓取 xst-zfkH`
**FileSplitterFetch.java 5$i(f8*
*/ u.E>d9
package NetFox; r?KRK?I
F=5+JjrX
)]n>.ZmLCB
import java.io.*; g Cp`J(2v:
import java.net.*; o^@#pU <
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[__P-h{J
public class FileSplitterFetch extends Thread { Fs>MFj
[XPAI["
r@JMf)a]
String sURL; //File URL Zzlt^#KLx
long nStartPos; //File Snippet Start Position =lv(
long nEndPos; //File Snippet End Position ll}_EUF|
int nThreadID; //Thread's ID :E{)yT
boolean bDownOver = false; //Downing is over <\nM5-wR
boolean bStop = false; //Stop identical $c*fbBM(&n
FileAccessI fileAccessI = null; //File Access interface O:v#M]
.joCZKO
]prw=rD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E2l"e?AN~
{ h~QQ-
this.sURL = sURL; y%|Ez
this.nStartPos = nStart; aP(~l_
this.nEndPos = nEnd; aGWO3Nk
nThreadID = id; >07i"a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !UT!PX)
} 75>%!mhM
Y"ta`+VJ
/1TK+E$
public void run() Dj= {%
{ )4o8SF7lz
while(nStartPos < nEndPos && !bStop) |`yU \
{ DK2Wjr;
b73}|4v
S%H"i y
try{ RJ'za1@z;b
URL url = new URL(sURL); "r`2V-E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c}v8j2{
httpConnection.setRequestProperty("User-Agent","NetFox"); NI/'SMj%
String sProperty = "bytes="+nStartPos+"-"; @Y,t]
httpConnection.setRequestProperty("RANGE",sProperty); =Crl{Ax
Utility.log(sProperty); %#fjtbeB
ka=A:biz
A|Ft:_Y
InputStream input = httpConnection.getInputStream(); ZYY`f/qi
//logResponseHead(httpConnection); 37n2#E
AW;xlY= g
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byte[] b = new byte[1024]; pv4#`.m
int nRead; BZOl&G(
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) dJzaP
{ E*R-Dno_F
nStartPos += fileAccessI.write(b,0,nRead); GRpwEfG
//if(nThreadID == 1) t<+>E_Xw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m Urb
} "cS7E5-|
0^L:`[W+
~Y0K Wx4
Utility.log("Thread " + nThreadID + " is over!"); ;"f9"
bDownOver = true; -~sW@u)O
//nPos = fileAccessI.write (b,0,nRead); f*V^HfiQb
} p%Q{Rqc)
catch(Exception e){e.printStackTrace ();} io"NqR#"v
} zp4@T)
} J*ofa>
lX.1B&T9Lr
|-v/
//打印回应的头信息 (gdzgLHy
public void logResponseHead(HttpURLConnection con) UQI!/6F
{ d:Z|It
for(int i=1;;i++) )-XD= ]
{ 8xj_)=(sV!
String header=con.getHeaderFieldKey(i); )4ok@^.
if(header!=null) &]f8Xd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); F:Vl\YZ
Utility.log(header+" : "+con.getHeaderField(header)); , iEGf-!k
else 8~!h8bkC
break; f&F9ImZ
} >y}> 5kv
} 7u1o>a%9
hQ)?LPUB
Yjy%MR
public void splitterStop() 8eCh5*_$
{ amQiH!}8R
bStop = true; }If,O
} $/u.F;
>7?Lq<H
"<L9-vb
} gjJ:s,Fg
W;X:U.
EnMc9FN(y
/* 1JS5 LS
**FileAccess.java 6DEH|2
*//文件访问(定位，写) 5a5JOl$8
package NetFox; 4X:mb}(
import java.io.*; YYe<StyH
AgDXpaq
C:!&g~{cKi
public class FileAccessI implements Serializable{ FIJ]`
(h&=Na~
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ) [)1
RandomAccessFile oSavedFile; fTy{`}>
long nPos; 3ug>,1:6-
2_6@&2
W$}2 $}r0U
public FileAccessI() throws IOException us#ji i.<
{ `y"a>gHC
this("",0); 3!KyO)8
} *TL3-S?
So NgDFD
wG 5H^>6u>
public FileAccessI(String sName,long nPos) throws IOException [MAvU?;
{ vA?3kfL|#
oSavedFile = new RandomAccessFile(sName,"rw"); }y|_v^
this.nPos = nPos; O/l/$pe
oSavedFile.seek(nPos); #E/|WT
} +D h?MQt?
?;rRR48T9E
9:!V":8q
public synchronized int write(byte[] b,int nStart,int nLen) >(gbUW
{ B.?@VF
int n = -1; t4zKI~cO
try{ PTF|"^k+
oSavedFile.write(b,nStart,nLen); [L2N[vy;
n = nLen; f 0/q{*
} _k)EqPYu@
catch(IOException e) }o=s"0a
{ `:gXQmt
e.printStackTrace (); UE/iq\a>
} oJc v D
?,r}@89pY
J32"Ytdo<
return n; ~. 5[
} n}J!?zZc
1mv8[^pF
Xq$9H@.
} \NL*$SnxP
q] '2'"k
!imjfkG
/* ?KFj=Yo
**SiteInfoBean.java |v"&Y
*/ ATD4%|a9h
package NetFox; opReAU'I
g|{Ru
.V{y9e+
public class SiteInfoBean { NE?tfj
fc^d3wH0L
hIo^/_K
private String sSiteURL; //Site's URL J)^Kls\>t
private String sFilePath; //Saved File's Path g0s*4E
private String sFileName; //Saved File's Name NV18~5#</
private int nSplitter; //Count of Splited Downloading File xf3/J{n3
kI^Pu
\lpvRZ\L&g
public SiteInfoBean() 9!Bz)dJ3
{//nSplitter的缺省值为5 LII4sf]
//default value of nSplitter is 5 JF9r[%
this("","","",5); Tu=~iQ
} fp$U%uj
2()/l9.O'
Y-v6M3$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^B'N\[
{ dJ7!je1N*
sSiteURL= sURL; ^Zq3K
sFilePath = sPath; LHusy;<E[
sFileName = sName; U1pwk[
this.nSplitter = nSpiltter; Wl{}>F`W[
sWMY Lo
_3m\r*(vmQ
} 'q{d? K
oazy%n(KZ
cx+%lco!
public String getSSiteURL() TxmKmZ u
{ RxGZ#!j/
return sSiteURL; s,8g^aF4
} SuJ4)f;'0
8^qLGUxz
Dp;6CGYl?
public void setSSiteURL(String value) oN.#q$\` k
{ RA:3ZV
sSiteURL = value; e8hwXz
} I*= =I4qx
hODq&9!
F t;[>o
public String getSFilePath() BA`K,#Ft7
{ 6z1>(Za7>
return sFilePath; <w0$0ku
} =\x(Rs3
IUwMIHq&sW
aeTVcq
public void setSFilePath(String value) HhT6gJWrU
{ a>)|SfsE
sFilePath = value; /~_,p,:aP
} j<-YK4.t
?`=r@
F'JceU
public String getSFileName() a*{ -r]
{ 1y6{3AZm<
return sFileName; 5H/D~hr&
} 3/RNStd<L!
),U>AiF]
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public void setSFileName(String value) kSU]~x
{ '>dx~v %
sFileName = value; fqD1Ej
} JX2@i8[~
u|M_O5^
ivP#qM1*;
public int getNSplitter() j# !U6T
{ oTxE]a,
return nSplitter; e'5sT#T9l
} \t%rIr
5VK.Zs\
69EdMuf
public void setNSplitter(int nCount) )\fLS d
{ P~ODd(
nSplitter = nCount; c>yqq'
} //-;uEO
} U<.,"`=l
$g]'$PB
(b;*8
/* 'mE!,KeS;
**Utility.java t(5PKD#~Dc
*/ Zf8_ko;|:-
package NetFox; nY50dFA,
"/$2oYNy+
l5CFm8%
public class Utility { x10u?@
"DU1k6XC
okQ<_1e{
public Utility() J=AF`[
{ ?bH!|aW(H
^mCKRWOP'
|lVoL.Z,0
} _*LgpZ-2(
W60C$*h
//线程睡眠 +|TFxaVz
public static void sleep(int nSecond) ;n;bap
{ Eh/Z4pzT
try{ eaCh;IpIf
Thread.sleep(nSecond); !5=S2<UX
} }J|Pd3Q Sf
catch(Exception e) pn-`QB:{h
{ 8;1,saA_9
e.printStackTrace (); !t!\b9=
} b[`fQv$G
} /zZ";4
O}mz@-Z
//日志 7':qx}c#!1
public static void log(String sMsg) db5@+_
{ )|`|Usn#[
System.err.println(sMsg); zJX _EO
} db0]D\
])H[>.?K
XPsRa[08WK
public static void log(int sMsg) .|z8WF*
{ j55;E E!
System.err.println(sMsg); qCku q
} 0`%Ask
} 'fr~1pmx#3
H&E3RU>`
/O&{fo
/* ,RIC _26
**TestMethod.java B"=w9w]
*/ XCUU(H
package NetFox; ^QTtCt^:
TIYo&?Z)
jltW@co2sV
public class TestMethod { .p$tb2%r
{bD:OF
v2;'F
public TestMethod() dxK3462
{ ///xx/weblogic60b2_win.exe P1IL]
try{ :DoE_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); w-wap
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /7jb&f
SiteFileFetch fileFetch = new SiteFileFetch(bean); m%)Cw)t 7
fileFetch.start(); wC`+^>WFo
} m)Sdogt_
catch(Exception e){e.printStackTrace ();} nX|]JW
9A!B|s
F0]xc
} LMTz/M
uwo\FI
EaUO>S
public static void main(String[] args) #d;/Me
{ 4"~l^yK
new TestMethod(); Z|6,*XEc
} $BUm,
} s{dgUX
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