http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); u6agoK|^9
} +\9NDfYIA
for(int i=0;i<nEndPos.length-1;i++) H <l7ZS:
{ TJRCH>E[a
nEndPos = nStartPos[i+1]; ##*3bDf$-5
} R 9\*#c
nEndPos[nEndPos.length-1] = nFileLength; Yq KCeg
} %u'ukcL7
} uXvtfc
/4Gt{ygSr
m_]Y{3C
//启动子线程 :F?C)F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %h@EP[\
for(int i=0;i<nStartPos.length;i++) vs4>T^8e
{ '=pU^Oz<}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3w'tH4C[Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Nf\LN$ &8
nStartPos,nEndPos,i); o+'6`g'8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0l6.<-f{
fileSplitterFetch.start(); (<9u-HF#
} 8A#;WG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4hj|cCrO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S9.o/mr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 77Dn97l)&
nEndPos = " + nFileLength); 7@Qcc t4A
// fileSplitterFetch[nPos.length-1].start(); ZECfR>`x
e^voW"?%
<5051UEu
//等待子线程结束 2+XAX:YD
//int count = 0; ;V!D:5U
//是否结束while循环 @VEb{ w[H
boolean breakWhile = false; }K(TjZR
9*M,R,y
@yYkti;4-
while(!bStop) F^:3?JA_
{ t6c4+D'{].
write_nPos(); gbA_DZ
Utility.sleep(500); B+`g>h
breakWhile = true; CU0YIL
ob]w;"
W>r+h-kR
for(int i=0;i<nStartPos.length;i++) J&_n9$
{ RA 6w}:sq7
if(!fileSplitterFetch.bDownOver) 9(Xn>G'iT
{ Di{de`
breakWhile = false; wCBplaojJ
break; :ws<-Qy
} At;LO9T3z
} h?U O&(
if(breakWhile) 3v-~K)hl?
break; Vurqt_nb
%cn<ych G
SpBy3wd
//count++; DEgXQ[
//if(count>4) LghfM"g
// siteStop(); u ga_T
} 6u6x
A#,ZUOPGH
;'1d1\wiDQ
System.err.println("文件下载结束！"); V7/Rby Q
} [}m[)L\
catch(Exception e){e.printStackTrace ();} gX@aG9
} DlJo^|5
*T1_;4i
{!`6zBsP
//获得文件长度 HzJz+ x:
public long getFileSize() ]?4hyN
{ -Y8B~@]P?
int nFileLength = -1; Fr-SvsNFB
try{ 7tp36TE
URL url = new URL(siteInfoBean.getSSiteURL()); 3so%gvY.'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); l]SX@zTb
httpConnection.setRequestProperty("User-Agent","NetFox"); ='jT~\
zbiLP83
0g;|y4SN=
int responseCode=httpConnection.getResponseCode(); Z_NCD`i;
if(responseCode>=400) =_^X3z0
{ a+QpM*n7Lq
processErrorCode(responseCode); Ny#^&-K
return -2; //-2 represent access is error Gc7=
} '3;b@g,
q^nVN#
W,u:gzmhw
String sHeader; wd6owr
&^nGtW%a 9
vDvFL<`vmD
for(int i=1;;i++) nk:)j:fr
{ hbn([+xY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \M-OC5fQv
//Utility.log(in.readLine()); O/LXdz0B
sHeader=httpConnection.getHeaderFieldKey(i); !r-F>!~
if(sHeader!=null) Q2>gU#
{ :Dp0?&_
if(sHeader.equals("Content-Length")) []T8k9g/-
{ 5r0YA IJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lhJ'bYI
break; :6dxtl/{b:
} Y);=TM6s
} I1J-)R+
else AZ<=o
break; PvL[e"p
} ^zr`;cJ+c
} Y/oHu@ _
catch(IOException e){e.printStackTrace ();} +C)~bb*
catch(Exception e){e.printStackTrace ();} i#O SC5ZI
D_MmW
lquLT6]
Utility.log(nFileLength); A}!J$V:w]
.\mj4*?/
(<lhn
return nFileLength; P<-@h1p,
} TA\vZGJ('
Gm`8q}<I
,%y/kS]
//保存下载信息（文件指针位置） {`_i`
private void write_nPos() +T+#q@
{ |y*c9
try{ Rb;'O89Hj@
output = new DataOutputStream(new FileOutputStream(tmpFile)); F"kAkX>3}
output.writeInt(nStartPos.length); rM SZ"
for(int i=0;i<nStartPos.length;i++) 3g B7g'U
{ ^rz_f{c]-
// output.writeLong(nPos); C#pjmT_
output.writeLong(fileSplitterFetch.nStartPos); /_.|E]
output.writeLong(fileSplitterFetch.nEndPos); CN?gq^
} p4QU9DF
output.close(); s#MPX3itK
} FTldR;}(
catch(IOException e){e.printStackTrace ();} %2h>-.tY
catch(Exception e){e.printStackTrace ();} 8XaQAy%d]
} |BYRe1l6l
iRBfx
C,zohlpC
//读取保存的下载信息（文件指针位置） )B*t :tN
private void read_nPos() kf9X$d6
{ ; @X<lCk
try{ Bp{Ri_&A
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bK7J}8hH
int nCount = input.readInt(); I 6O
nStartPos = new long[nCount]; g{LP7D;6
nEndPos = new long[nCount]; YZ7.1`8
for(int i=0;i<nStartPos.length;i++) z!\*Y =e
{ r|Z{-*`
nStartPos = input.readLong(); ABkl%m6xf
nEndPos = input.readLong(); "jCu6Rjd
} _dg\\c
input.close(); <naz+QK'
} [B3RfCV{
catch(IOException e){e.printStackTrace ();} 0"#HJA44
catch(Exception e){e.printStackTrace ();} /@5YW"1
} 13f)&#, F
)}vl\7=
P {'b:C
private void processErrorCode(int nErrorCode) `_h&glMJ,q
{ [hsds\
System.err.println("Error Code : " + nErrorCode); 8k79&|
} P~dcW
=u;MCQ[
P2Y^d#jO
//停止文件下载 !9x}
public void siteStop() R-Sym8c
{ >sbu<|]a 7
bStop = true; S>{~nOYt-`
for(int i=0;i<nStartPos.length;i++) =c7;r]Ol
fileSplitterFetch.splitterStop(); n!(F, b
/RF7j;
IA(5?7x`<
} 7z-[f'EIUI
} ^Dx&|UwiZa
//负责部分文件的抓取 _cwpA#x`}
**FileSplitterFetch.java )e{}V\;q
*/ QW"! (`K
package NetFox; Pz^544\~ou
$!DpjN
_B0L.eF
import java.io.*; \v/[6&|X0s
import java.net.*; Ss`LLq0LO
0IpmRH/
ntY]SK%Z
public class FileSplitterFetch extends Thread { _4f;<FL
W9)&!&<o
9FX-1,Jx
String sURL; //File URL 1eKT^bgM
long nStartPos; //File Snippet Start Position "5 A!jq
long nEndPos; //File Snippet End Position r :dTz
int nThreadID; //Thread's ID /<3UQLMa
boolean bDownOver = false; //Downing is over 1&2>LE/P
boolean bStop = false; //Stop identical fR|A(u#9
FileAccessI fileAccessI = null; //File Access interface T;#FEzBz
Wjc'*QCPl
3oqHGA:}
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {b{s<@?
{ 54/=G(F
this.sURL = sURL; (w{j6).3Dj
this.nStartPos = nStart; %3rP`A
this.nEndPos = nEnd; -HuA \0J
nThreadID = id; x"~JR\yzKJ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wS*E(IAl
} Y ay?=Y{
Mfs?x a
A=4OWV?
public void run() j39wA~K
{ 0`hdMLONR
while(nStartPos < nEndPos && !bStop) 9VT;ep
{ xkn;,`t^lJ
v2?ZQeHr_(
5)E @F9N
try{ S[N5 ikg
URL url = new URL(sURL); W4N{S.#!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F5Va+z,jg
httpConnection.setRequestProperty("User-Agent","NetFox"); +qoRP2
String sProperty = "bytes="+nStartPos+"-"; ;);kEq/=P
httpConnection.setRequestProperty("RANGE",sProperty); h\e.e3/
Utility.log(sProperty); Y0>y8UV
*2?@ |<(r
&FD>&WRV
InputStream input = httpConnection.getInputStream(); iB{V^ksU
//logResponseHead(httpConnection); fIF8%J ^3
7 3m1
f<H2-(m
byte[] b = new byte[1024]; Q;u pau
int nRead; HV.t6@\};
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) O84i;S+-p
{ &NWEqBz*2
nStartPos += fileAccessI.write(b,0,nRead); g'gdgfvn
//if(nThreadID == 1) #S(Hd?34,
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v1[29t<I!
} =fbWz
:r[`.`
wbHb;]
Utility.log("Thread " + nThreadID + " is over!"); `]X>V,
bDownOver = true; +0~YP*I`/
//nPos = fileAccessI.write (b,0,nRead); d5.4l&\u
} 2|L&DF:G
catch(Exception e){e.printStackTrace ();} PdCEUh\>y
} 9my^Y9B
} q7!{?\T%
] @'!lhLi
xUvs:
//打印回应的头信息 99S^f:t
public void logResponseHead(HttpURLConnection con) dscgj5b1~
{ P%6~&woF
for(int i=1;;i++) <m m[S
{ i$@:@&(~Y
String header=con.getHeaderFieldKey(i); T|p"0b A
if(header!=null) yZRzIb_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); N$DkX)Z
Utility.log(header+" : "+con.getHeaderField(header)); VnzZTGs
else d@^ZSy>L2
break; u"8yK5!
} Q@niNDaW2
} zTp"AuNHN
hc1N~$3!G
=WLY6)]A
public void splitterStop() SIllU
{ yr6V3],Tp
bStop = true; "zc l|@
} nEfK53i_
O=lzT~G|4
[}:$yg
} nu^436MSOa
]yu:i-SfP
G6/m#
/* >0gW4!7Y
**FileAccess.java pJ=#zsE0
*//文件访问(定位，写) ;*N5Y}?j'
package NetFox; :Al!1BJQ
import java.io.*; C+]I@Go'Tk
u!s2BC0}N
z{6Z 11|
public class FileAccessI implements Serializable{ T+$[eWk"a
@7u0v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [m -bV$-d
RandomAccessFile oSavedFile; =v\.h=~~
long nPos; ,I9bNO,%JK
BWNi [^]
lFkR=!?=
public FileAccessI() throws IOException 7,MR*TO,
{ s*4dxnS_8
this("",0); \^LFkp
} <$YlH@;)`a
vIvIfE
Y@v>FlqI{
public FileAccessI(String sName,long nPos) throws IOException YQ}o?Q$z
{ . me;.,$#
oSavedFile = new RandomAccessFile(sName,"rw"); .X&9Q9T=#
this.nPos = nPos; ^pS~Z~[d/
oSavedFile.seek(nPos); jo7\`#(Q
} t:S+%u U
LP-o8c
=AT."$r>
public synchronized int write(byte[] b,int nStart,int nLen) So6x"1B
{ IgzQr>
int n = -1; 3R/bz0 V>
try{ Zfw,7am/
oSavedFile.write(b,nStart,nLen); *Ly6`HZ9
n = nLen; 5(2;|I,T
} 0_/[k*Re
catch(IOException e) y} '@R$
{ l}h!B_P'
e.printStackTrace (); dQvcXl]
} 8|^7ai[am
xo)P?-
@iiT<
return n; hoP]9&<T
} / 1RpM]d
#Y!a6h+
VUc%4U{Cti
} ("@!>|H
}\f0 A-
Mt$ *a
/* B?QIN]
**SiteInfoBean.java s.rm7r@#
*/ b>W%t
package NetFox; R_KH"`q
$qiya[&G4
im8CmQ
public class SiteInfoBean { B~mj 8l4
:s,Z<^5a)g
~u{uZ(~
private String sSiteURL; //Site's URL SM'|+ d
private String sFilePath; //Saved File's Path 0K+ne0I
private String sFileName; //Saved File's Name do_[&
private int nSplitter; //Count of Splited Downloading File 3$tdwe$S
|)&%A%m
GyIV Hby
public SiteInfoBean() Xvv6~
{//nSplitter的缺省值为5 7$b1<.WX
//default value of nSplitter is 5 H\ %7%
this("","","",5); J,hCvm
} mw!F{pw
'91/md5
29rX%09T]
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _$'ashF
{ /z!%d%"
sSiteURL= sURL; }C:r9?T
sFilePath = sPath; \zY!qpX<
sFileName = sName; O^.#d
this.nSplitter = nSpiltter; ~&T~1xsFJ
\m,PA'nd/
XX@ZQcN
} dG{A~Z z
Y*^[P,+J*}
0@(&eH=
public String getSSiteURL() EPm/r
{ ;jXgAAz7
return sSiteURL; *hx
} yfSmDPh
hM{bavd
`A>@]d
public void setSSiteURL(String value) +TJCLZ..
{ -"`=1l
sSiteURL = value; Ulyue
} =&]L00u.
^c<Ve'-
Wri<h:1
public String getSFilePath() bsX[UF
{ pkzaNY/q
return sFilePath; DrR@n~
} WY/}1X9.%
\bcLiKE{
KwS@D9bok
public void setSFilePath(String value) tc! #wd+u
{ uYN`:b8
sFilePath = value; -~1~I e2
} TxD#9]Q`
2 nCA<&
6'/ #+,d'
public String getSFileName() _U(
{ Nc`L;CP
return sFileName; Y|n"dMrL
} "[J^YKoF
DI>s-7
e= AKD#
public void setSFileName(String value) wj,=$RX
{ +whDU2 "
sFileName = value; q1,~
} <YY14p
#a6iuO0I
$mILoy B,
public int getNSplitter() !a`&O-ye
{ N)T}P\l
return nSplitter; ]esC[r]PJ
} ^sw?gH*
RP"kC4~1
aOp\91
public void setNSplitter(int nCount) wT@og|M
{ icgfB-1|i
nSplitter = nCount; O-^Ma-}
} CZ;6@{ o
} Y7|EIAU5Y
w{KavU5W
Hka2
/* L,\Iasv
**Utility.java aUp g u"
*/ ]9CFIh
package NetFox; ^!d3=}:0
iTwm3V P
;pAK_>
public class Utility { GOPfXtkC
;p//QJB9
s[jTP(d)8
public Utility() uT"rq:N
{ G\i9:7 `
9w"*y#_
zPO9!?7|
} V!Uc(
TOt dUO
//线程睡眠 & 21%zPm
public static void sleep(int nSecond) ZVBXx\{s
{ .Mbz3;i0
try{ l#o ~W`
Thread.sleep(nSecond); aN?zmkPpov
} /: "1Z]@
catch(Exception e) a(nlTMfu
{ dd;~K&_Q/i
e.printStackTrace (); ?9/G[[(
} o&%g8=n%
} .*oU]N%K=
i5Ggf"![
//日志 23PGq%R
public static void log(String sMsg) _>+Ld6.T6
{ lxx2H1([
System.err.println(sMsg); RZLq]8pM
} FrS]|=LJhX
Ui~>SN>s
1}x%%RD_
public static void log(int sMsg) HJ"GnZp<
{ uRvP hkqm
System.err.println(sMsg); ,+k\p5P
} 0mE 0 j
} Ud?Q%)X
^qs $v06
tQ)qCk07
/* _6Sp QW
**TestMethod.java 6P3*Z
*/ oJ^P(]dw
package NetFox; X?O[r3<
ah"o~Cbj
l?e.9o2-
public class TestMethod { r!v\"6:OM
D.:Zx
?,z}%p
public TestMethod() $Sq:q0
{ ///xx/weblogic60b2_win.exe wk^B"+Uhy
try{ IGl9g_18
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Oketwa
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2y4bwi
SiteFileFetch fileFetch = new SiteFileFetch(bean); *dQSw)R
fileFetch.start(); ES[G
} f*Hr^b}`8
catch(Exception e){e.printStackTrace ();} z{ dEC %
&C}*w2]0S
=_CzH(=f#
} "oyo#-5z
}BEB1Q}L
w;M#c Y
public static void main(String[] args) 81F9uM0
{ OUnA;_
new TestMethod(); Rq-ZL{LR7
} VbYdZCC
} )%TmAaj9d
点击下载更多相关资料