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)); JO\Tf."a\
} n3t1'_/TU}
for(int i=0;i<nEndPos.length-1;i++) [H)NkR;I
{ v]\io#
nEndPos = nStartPos[i+1]; ]+;1)
} 0ohpJh61Q
nEndPos[nEndPos.length-1] = nFileLength; CdgZq\
} :zdMV6s
} j9n3
dqO!p6
_"_ W KlN
//启动子线程 ~Z!!wDHS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }UJS*mR
for(int i=0;i<nStartPos.length;i++) (m80isl
{ |>@Gbgw^M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CwZ+Pn0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =)vmX0vL
nStartPos,nEndPos,i); /fbI4&SB!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $7eO33Bm
fileSplitterFetch.start(); i71,
} md:$OC3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y~EKMowI&e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 3XdN\xc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @-nCK Yj
nEndPos = " + nFileLength); Yh)yp?
// fileSplitterFetch[nPos.length-1].start(); S/G6NBnbS
&cztUM(
,}2yxo;i
//等待子线程结束 QEK,mc3
//int count = 0; OY7\*wc:
//是否结束while循环 q+f]E&':
boolean breakWhile = false; ..6 : _{wg
rq?:I:0
5_Yl!=
while(!bStop) 2*Hw6@Jj
{ BTjfzfO"
write_nPos(); < .&t'W
Utility.sleep(500); \PU3{_G]
breakWhile = true; 0&T0Ls#4
LWE[]1=
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for(int i=0;i<nStartPos.length;i++) bg;NBoZd
{ FJKW=1=,
if(!fileSplitterFetch.bDownOver) +6t<FH
{ V{@ xhW0
breakWhile = false; Z_Jprp{3h
break; :=vB|Ch:~
} k<RJSK8
} .WM0x{t/
if(breakWhile) w^MU$ubx
break; {WUW.(^]G
N p9N#m?
48dIh\TH"
//count++; Kk+IUs
//if(count>4) ;ZZ%(P=-
// siteStop(); hV|pH)Nu{
} Bv_C *vW
Y)^qF)v,d
RNGTSz
System.err.println("文件下载结束！"); XzI c<81Z
} rB|Mp!g%@
catch(Exception e){e.printStackTrace ();} M,@\*qlEJ
} {;0j9rr
'WK}T)o
Gc2sY 0
//获得文件长度 S!Ue+jW
public long getFileSize() U]j4Izq
{ su6x okt
int nFileLength = -1; f"t\-ux.b
try{ {o"X8
URL url = new URL(siteInfoBean.getSSiteURL()); IPmSkK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C{>@b:]p
httpConnection.setRequestProperty("User-Agent","NetFox"); ?hUC#{
&os9K)
92_F8y*D
int responseCode=httpConnection.getResponseCode(); # D"TY-$.=
if(responseCode>=400) TP'
{ 9n{tbabJ
processErrorCode(responseCode); OJ8ac6cJ
return -2; //-2 represent access is error !9=hUpRN
} iTsmUq<b]l
Qj: D=j8
'7G'R
String sHeader; cmgI,n-o?
?:l3O_U5
,9<}V;(
for(int i=1;;i++) 2%4dA$H#4w
{ &.z: i5&o!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); MMCac6;Aea
//Utility.log(in.readLine()); ^2E\{$J
sHeader=httpConnection.getHeaderFieldKey(i); Eyi^N0
if(sHeader!=null) `s#0/t
{ jn vJ`7zFP
if(sHeader.equals("Content-Length")) Jj+|>(P
{ 3 EH/6
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); H~%HTl
break; &ywAzGV{s
} $z,lq#zzl
} j<H`<S
else 0,+RF"R
break; %T@3-V_
} Cj31>k1
} ?B ;+,
catch(IOException e){e.printStackTrace ();} P#-9{T
catch(Exception e){e.printStackTrace ();} y<mmv~=
$;NxO0$
)6U&^9=
Utility.log(nFileLength); ;okFm
`tA~"J$32l
K];`
return nFileLength; {3=M-U~r
} am.}2QZU
%!%G\nv
\GYh"5
//保存下载信息（文件指针位置） T0BFit6
private void write_nPos() =Q|_v}
{ u&Q2/Y
try{ ol]"r5#Q_H
output = new DataOutputStream(new FileOutputStream(tmpFile)); _mVq9nBEf
output.writeInt(nStartPos.length); ~EJVlji
for(int i=0;i<nStartPos.length;i++) ,E,oz{,i(
{ *,qW9z
// output.writeLong(nPos); $YuVM
output.writeLong(fileSplitterFetch.nStartPos); c{4C4'GD
output.writeLong(fileSplitterFetch.nEndPos); D?;8bI%"
} 2)}ic2]pn
output.close(); {n9]ej^
} SXX6EIJr|
catch(IOException e){e.printStackTrace ();} LWgYGXWT"
catch(Exception e){e.printStackTrace ();} mU.(aLHW
} iXt1{VP'K
J.'}R2gT1
t.wB\Kmt\
//读取保存的下载信息（文件指针位置） 1L722I@
private void read_nPos() ph\KTLU
{ 0>hV?A
try{ F FHk0!3
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $s$j</.q
int nCount = input.readInt(); h+EG) <
nStartPos = new long[nCount]; dqwCyYC
nEndPos = new long[nCount]; 5bU[uT,`6
for(int i=0;i<nStartPos.length;i++) *L_+rJj,
{ Pd-0u>k
nStartPos = input.readLong(); ^Wb|Pl
nEndPos = input.readLong(); 0<f\bY02
} N-* ^V^V
input.close(); )IUeWR
} gBM6{48GF
catch(IOException e){e.printStackTrace ();} RC(fhqV
catch(Exception e){e.printStackTrace ();} r;:5P%:
} !DsKa6Zj
=xwA'D9]
^M?O
private void processErrorCode(int nErrorCode) s))L^|6
{ U~!yGjF
System.err.println("Error Code : " + nErrorCode); I4]|r k9
} cHN eiOF
>C,=elM
c%p7?3Ry
//停止文件下载 S[p.`<{J
public void siteStop() 7_t\wmvYp
{ N"-</kzV
bStop = true; 9MfBsp}c
for(int i=0;i<nStartPos.length;i++) E?%SOU<
fileSplitterFetch.splitterStop(); [@ExR*
W vh3Y,|3
Q1tZ]Q.6
} ?VC[%sjwn
} 5 :O7cBr
//负责部分文件的抓取 m$nT#@l5bH
**FileSplitterFetch.java ,G2]3 3Z
*/ ^R\et.W`s
package NetFox; !OwRx5
bvyX(^I[q
yZ7aH|Q81B
import java.io.*; ^7Sk`V
import java.net.*; [k~V77w 14
4`Com~`6"
>KF1]/y<
public class FileSplitterFetch extends Thread { Y1e>P
!uaV6K
{2u#Q7]|
String sURL; //File URL aLr\Uq,83
long nStartPos; //File Snippet Start Position &YMz3ugI
long nEndPos; //File Snippet End Position 9qyA{ |3
int nThreadID; //Thread's ID Ejc%DSG
boolean bDownOver = false; //Downing is over 5I#L|+
boolean bStop = false; //Stop identical TR2X' `:O
FileAccessI fileAccessI = null; //File Access interface 9+'QH
t~mbe
Z}#,E;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q-<,+[/
{ .&Uu w
this.sURL = sURL; ;r(hZ%pD
this.nStartPos = nStart; n_G< /8
this.nEndPos = nEnd; FPM@%U
nThreadID = id; _-^bAr`z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 S3cjw9V
} z[xi
MQD%m ;[s
_TF\y@hF*D
public void run() Fa
{ $nR1AOm}.B
while(nStartPos < nEndPos && !bStop) c\2+f7o@
{ jKFypIZ4
N}ur0 'J0
V6)e Jy
try{ bWc3a
URL url = new URL(sURL); Y\e,#y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Z/<HP$#
httpConnection.setRequestProperty("User-Agent","NetFox"); z#qlu=
String sProperty = "bytes="+nStartPos+"-"; foh>8/AL/
httpConnection.setRequestProperty("RANGE",sProperty); &(H;Bin'
Utility.log(sProperty); B>kx$_~
4;G:.k!K
tvNh@it:F
InputStream input = httpConnection.getInputStream(); 0Q@ &z
//logResponseHead(httpConnection); om$x;L6
EL_rh TWw
i <KWFF#
byte[] b = new byte[1024]; <]f ru1
int nRead; dB{o-R
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pJM~'tlHV
{ &Nf10%J'<
nStartPos += fileAccessI.write(b,0,nRead); Tac7+=T
//if(nThreadID == 1) JffjGf-o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N[$bP)h7
} . J"g.Q
d*7nz=0&$
L<HJ!
Utility.log("Thread " + nThreadID + " is over!"); S\7-u\)
bDownOver = true; PoyY}Ra
//nPos = fileAccessI.write (b,0,nRead); "PA:
} b21c} rI3
catch(Exception e){e.printStackTrace ();} aAHx^X^
} W,</
} <~9z.v7
oj.f uJD
D ==H{c1F
//打印回应的头信息 U1pL `P1
public void logResponseHead(HttpURLConnection con) N?!]^jI,
{ q,k/@@Qd9
for(int i=1;;i++) qTM,'7Rwn
{ *ea%KE":
String header=con.getHeaderFieldKey(i); #R_IF&7
if(header!=null) <5qXC.{Cyp
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0@w8,x
Utility.log(header+" : "+con.getHeaderField(header)); :r0?[#r?N,
else )6?(K"T
break; a]NQlsE}l
} dZnAdlJ
} lq2P10j@
rCGyr}(NC
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public void splitterStop() 2{!o"6t
{ Kk?P89=*
bStop = true; ia.95H;
} N(<4nAE
ElNKCj<M
Xo[={2_
} Ktrqrl^IJ
8BUPvaP<[
m9My
/* '~?\NeO=
**FileAccess.java 32[lsU>1
*//文件访问(定位，写) h-B&m:gD_U
package NetFox; xL,;(F\^
import java.io.*; n[Jpy[4g
98u$5=Z'/
VEAf,{)Q
public class FileAccessI implements Serializable{ eNN)2-96
?+Sjt
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;q:.&dak1
RandomAccessFile oSavedFile; 2BA'Zu`
long nPos; NUVFG;
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`Q d_Gu,M
public FileAccessI() throws IOException a4gJ-FE
{ %%["&
this("",0); KCR6@{@
} <dxc"A
Ps3wg=ni[
<ptZY.8N
public FileAccessI(String sName,long nPos) throws IOException 7TCY$RcF,I
{ T_}9b
oSavedFile = new RandomAccessFile(sName,"rw"); >5Vv6_CI0?
this.nPos = nPos; H+&c=~D\_
oSavedFile.seek(nPos); {(r`&[
} > %5<fK2
+o]DT7W
-3 .Sr|t
public synchronized int write(byte[] b,int nStart,int nLen) -eH5s3:A
{ Yj+p^@{S2P
int n = -1; OZ2gIK
try{ n_[;2XQQ
oSavedFile.write(b,nStart,nLen); d+P<nI/|
n = nLen; s)HLFdis@
} }^).Y7{g[
catch(IOException e) -LAYj:4
{ %5|awWo_?
e.printStackTrace (); z:B4
} VfS&V*un
}E626d}uA
;c1ar)G7
return n; <=;#I_E#E
} 4L(/Z}(
(=n{LMa
3z$9jN/<u
} "M.\Z9BCt
'l,ym~R
d{?X:*F
/* LF\4>(C2g
**SiteInfoBean.java .t\#>Fe
*/ }Gmwm|`*
package NetFox; |E/r64T
`w@8i[2J
&)4#0L4
public class SiteInfoBean { 5;{Q >n
p^u;]~JO
&rY73qfP'
private String sSiteURL; //Site's URL 'CiV=&3/
private String sFilePath; //Saved File's Path 9r,)Bw!RP
private String sFileName; //Saved File's Name r(g:b ^S
private int nSplitter; //Count of Splited Downloading File %fY\vd2
Y.9s-g
K0hmRR=
public SiteInfoBean() WP/?(%#Y
{//nSplitter的缺省值为5 eEvE3=,hg
//default value of nSplitter is 5 y\M]\^[7
this("","","",5); #bN'N@|
} DEj6 ky
@LQe[`
!zc?o?~z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nksx|i l
{ {OA2';3
sSiteURL= sURL; ~\;s}Fv.
sFilePath = sPath; ]3B8D<p
sFileName = sName; L\1&$|?
this.nSplitter = nSpiltter; u-yVc*<,
H_H3Gp
O}Y& @V%4k
} ~4e4Gyx c
mQ# 0c_
i8CO+Iv*{
public String getSSiteURL() 4hRc,Vq
{ *}mk$bA
return sSiteURL; cj=6_k
} |$AoI
:Fe}.* t
]iP +Y
public void setSSiteURL(String value) vwA d6Tm
{ TGUlJLT
sSiteURL = value; S6~&g|T,
} OsQB` D
L[M`LZpJo
Rd|#-7
public String getSFilePath() KmUH([#
{ 2y"]rUS`
return sFilePath; 46p%y
} &-l(nr]h]
A.`) 0dV
-u!{8S~wA
public void setSFilePath(String value) ZdcG6IG+
{ "n,?)
sFilePath = value; y2nwDw(xF
} Pe-1o#7~W
>M~wFs$~
QQ1|]/)
public String getSFileName() CF|4, K)
{ &x= PAu
return sFileName; )SJ18 no|l
} Ft} h&aYP
?4G/f<ou
W7R`})F
public void setSFileName(String value) IYZ$a/{P
{ 3m2hB%SNb
sFileName = value; >P-{2 a,4
} ExJch\
'fIBJ3s[o
>)V1aLu=
public int getNSplitter() aJAQ G
{ QC/%|M0 {
return nSplitter; >St]MS
} \piHdVD
)HaW# ,XB
]Ak/:pu
public void setNSplitter(int nCount) Zt3Y<3o
{ }iOFB&)w
nSplitter = nCount; 3rRN~$
} Y/|wOm;|
} f9ziSD#
P LHiQ:
-UTTJnu^
/* h_xHQf&#
**Utility.java xna4W|-
*/ yu^n;gWH
package NetFox; "2J$~2{N
Hi V7
-chk\75
public class Utility { 3Gr:.V9=
*=b#>//
Py}] {?
public Utility() Ug2^cgL
{ Y2Z<A(W
T/9`VB%N
"}91wfG9
} UoD@ix&0
/E%r@Rui3$
//线程睡眠 Uu}a! V
public static void sleep(int nSecond) N\f={O8E
{ Oo-%;l`&
try{ KV1/!r+*
Thread.sleep(nSecond); b@p3iq:
} VH>?%aL
catch(Exception e) [H-r0Ah
{ G/y@`A)
e.printStackTrace (); Y\Grf$e
} -n>JlfCd2
} B'@a36
{Xj2c]A1
//日志 iUH{rh!
public static void log(String sMsg) &I=27!S
{ v&#=1Zb
System.err.println(sMsg); Hea76P5$P+
} ug?])nO.C
z[E gMS!
. #7B10
public static void log(int sMsg) Y<h [5
{ [UW%(N
System.err.println(sMsg); AJ%x"
} IegZ)&_n
} -C
QP%*`t?
a,EApUWw
/* L2NO_N
**TestMethod.java +^@;J?O
*/ cW|M4`
package NetFox; cD!yd^QE
]TTQ;F
?J1x'/G
public class TestMethod { _7^4sR8=
p3f>;|uh_
d^.@~
public TestMethod() kN'.e*
{ ///xx/weblogic60b2_win.exe 2)W~7GED
try{ *!W<yNrR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z'@a@Y+
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); l7p*::(9
SiteFileFetch fileFetch = new SiteFileFetch(bean); !(&N{NH9
fileFetch.start(); '9w.~@7
} kr=&x)Wy!
catch(Exception e){e.printStackTrace ();} 4!3mSWNV
rNl`w.
83|7#L
} P p]Ygt'u
;DG&HO
vT&xM
public static void main(String[] args) c!2j+ORz
{ L'KgB=5K&i
new TestMethod(); CnvM>]
} X (0`"rjg
} L{i,.aE/nO
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