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)); nhxd
} 3$G25=eN
for(int i=0;i<nEndPos.length-1;i++) ]~ 8N
{ y?4=u,{C
nEndPos = nStartPos[i+1]; L$?~TY
} b6$A@b
nEndPos[nEndPos.length-1] = nFileLength; PaI63 !
} =xWW+w!r
} nk,Mo5iqV
MJR\ g3
x3F L/^S
//启动子线程 $R^"~|m3M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TiOvrp7B
for(int i=0;i<nStartPos.length;i++) 5Hr"}|J<8
{ 2}`OjVS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~6OdPD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /A>/]2(
nStartPos,nEndPos,i); Awj`6GeJ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 'HC4Q{b`
fileSplitterFetch.start(); .8,lhcpY
} 1*a2s2G '
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Y-Z.AA,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JeO(sj$e
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", R4o_zwWgPw
nEndPos = " + nFileLength); uto4bs:
// fileSplitterFetch[nPos.length-1].start(); FNUue
L.8-nTg"y
SDot0`s>
//等待子线程结束 AttDD{Ta
//int count = 0; S]<Hx_[}
//是否结束while循环 G6I>Ry[2?
boolean breakWhile = false; ^rx]Y;
z-()7WY
U?kJXM2
while(!bStop) {AB0 PM;-
{ 8&3G|m1-2
write_nPos(); 3D\I#g
Utility.sleep(500); FzNs >*
breakWhile = true; -qs9a}iL
wp} PQw:
xY@V.
for(int i=0;i<nStartPos.length;i++) vmL0H)q
{ lwa
if(!fileSplitterFetch.bDownOver) x;kW }U
{ xvb5-tK -
breakWhile = false; Og^b'Kx/
break; >R :Bkf-
} <zrGPwk
} hMDy;oQ
if(breakWhile) 3PPN_Z
break; {8'I+-
KYMz
Eqnc("m)
//count++; O\8_;Gc;
//if(count>4) Q`'w)aV
// siteStop(); xV}-[W5sr'
} (@[c;+x
HvLvSy1U
J1KV?aR
System.err.println("文件下载结束！"); +<7`Gn(n3
} (w`9*1NO
catch(Exception e){e.printStackTrace ();} C/U^8,6\n
} wgp{P>oBX
IXc"gO
ET.c8K1f
//获得文件长度 1#/>[B
public long getFileSize() ha&2V=
{ 3]$qY_|7
int nFileLength = -1; o)GLh^g_I'
try{ 5R"iF+p4
URL url = new URL(siteInfoBean.getSSiteURL()); <xv@us7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Yi:@>A<#
httpConnection.setRequestProperty("User-Agent","NetFox"); t4X:I&l-M:
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{)=h
int responseCode=httpConnection.getResponseCode(); L"e8S%UqX
if(responseCode>=400) gE;r;#Jt4
{ }V:ZGP#!'
processErrorCode(responseCode); js^+{~
return -2; //-2 represent access is error V $Y=JK@
} ]6#bp,
41dB4Td5t
G6@XRib3
String sHeader; X?kw=x{2P
xL&M8:
F`))qCgg]
for(int i=1;;i++) 9 M>.9~
{ F/.nr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 'ONCz
//Utility.log(in.readLine()); {B|)!_M#
sHeader=httpConnection.getHeaderFieldKey(i); K;)(fc
if(sHeader!=null) tr?U/YG
{ d%?$UnQ
if(sHeader.equals("Content-Length")) *,az`U
{ IPHZ~'M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CmP_9M?ce
break; :yFUlO:
} oyC5M+shP9
} m!#'4
else V)<Jj
break; ^?<gz!(-
} @'IRh9
} \k 9EimT}
catch(IOException e){e.printStackTrace ();} sH_B*cr3
catch(Exception e){e.printStackTrace ();} ^L4"X~eM
sx1w5rj.Y0
r{mj[N'@
Utility.log(nFileLength); 6>DmcG:.
w#qE#g %1
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return nFileLength; ka=EOiX.
} 0Ba*"/U]t~
O n/q&h5
xu<oQBt
//保存下载信息（文件指针位置） (baBi9<P=
private void write_nPos() [%LIW%t|
{ X:2)C-l?
try{ M4}b lh#
output = new DataOutputStream(new FileOutputStream(tmpFile)); BG/Q7s-?K
output.writeInt(nStartPos.length); y?P4EVknM3
for(int i=0;i<nStartPos.length;i++) &RB{0Qhx
{ _jWGwO
// output.writeLong(nPos); *N65B#
output.writeLong(fileSplitterFetch.nStartPos); 7MZ(tOR
output.writeLong(fileSplitterFetch.nEndPos); N!lQ;o'
} .dPy<6E
output.close(); sD=iHO Am
} Eg+z(m$M
catch(IOException e){e.printStackTrace ();} K#;EjR4H
catch(Exception e){e.printStackTrace ();} AFdBf6/"i
} Vw";< <0HZ
|V-)3#c
Lj2Au_5
//读取保存的下载信息（文件指针位置） W&=F<n`
private void read_nPos() $N/"c$50,
{ wOV}<.W
try{ I?OnEw
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q@ghQGn#
int nCount = input.readInt(); $s<bKju
nStartPos = new long[nCount]; AQgagE^
nEndPos = new long[nCount]; I><sK-3
for(int i=0;i<nStartPos.length;i++) m{?uR.O
{ I*4g ;1x
nStartPos = input.readLong(); M32Z3<
nEndPos = input.readLong(); w,VUWja
} p<8Ga.kiN
input.close(); iM_Zn!|@\
} L(`Rf0smt
catch(IOException e){e.printStackTrace ();} chszP{-@X
catch(Exception e){e.printStackTrace ();} &Xp<%[:
} -_T@kg[0zB
?bw1zYP
I%tJLdL
private void processErrorCode(int nErrorCode) VQ/Jz5^
{ 8dCa@r&tz
System.err.println("Error Code : " + nErrorCode); k|;[)gE
} LgJUMR8vUO
r8TNl@Z
}gtkO&
//停止文件下载 i1ss}JJp*
public void siteStop() V[fcP;
{ BkJNu_{m?
bStop = true; D)GD9MJ
for(int i=0;i<nStartPos.length;i++) +ieRpVg
fileSplitterFetch.splitterStop(); &? z6f9*$
lQl
&vV_,$
} ,#hx%$f}d
} %Kc2n9W
//负责部分文件的抓取 c~v(bK
**FileSplitterFetch.java by@}T@^\
*/ "FH03 9
package NetFox; tY0C& u2
<Kt;uu>
CSNfLGA
import java.io.*; MClvmv^
import java.net.*; sY@x(qkIOc
65AG#O5R
L0EF CQ7
public class FileSplitterFetch extends Thread { IrTMZG
B,avI&7M;S
?)mM]2%%
String sURL; //File URL \zv?r:1t
long nStartPos; //File Snippet Start Position (f>~+-IL
long nEndPos; //File Snippet End Position |z]--h
int nThreadID; //Thread's ID QTbv3#
boolean bDownOver = false; //Downing is over /d-d8n
boolean bStop = false; //Stop identical >q^l
FileAccessI fileAccessI = null; //File Access interface >Qold7 M
L>{p>
-Gn0TA2/C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException RqE|h6/
{ ~CQTPR
this.sURL = sURL; 7FvtWE*
this.nStartPos = nStart; BZ"+ ND9m_
this.nEndPos = nEnd; 2#t35fU
nThreadID = id; fFNwmH-jv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 -$+`v<[r
} a[A9(Ftn
UCL aCt -
9~6)u=4sS"
public void run() V]qv,>
{ ?R8wmE[w
while(nStartPos < nEndPos && !bStop) 1:VbbOu->V
{ i!DO
|)+;d
+c-?1j
try{ ncCgc5uP
URL url = new URL(sURL); uIb,n5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '980.
httpConnection.setRequestProperty("User-Agent","NetFox"); 3r]N\c
String sProperty = "bytes="+nStartPos+"-"; M8}t`q[-&
httpConnection.setRequestProperty("RANGE",sProperty); W&Pp5KR
Utility.log(sProperty); 0Z<&M|G
M^3pJ=;5
!i77v, (#|
InputStream input = httpConnection.getInputStream(); l-G] jXu
//logResponseHead(httpConnection); S=.7$PY
k7\ ,No}
f!n0kXVu6U
byte[] b = new byte[1024]; }Rx`uRx\
int nRead; F|3iKK022
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?OFl9%\ V
{ ERQc1G]3Dd
nStartPos += fileAccessI.write(b,0,nRead); @.SuHd
//if(nThreadID == 1) xhmrep6+<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 67{>x[
} g7r_jj%ow
#FQkwX'g
a }m>
Utility.log("Thread " + nThreadID + " is over!"); gvl3NQQ%t
bDownOver = true; MzudCMF
//nPos = fileAccessI.write (b,0,nRead); 8BgHoQ*
} p ! _\a
catch(Exception e){e.printStackTrace ();} P/hV{@x
} -IF3'VG
} QaYUcma~n
JX!@j3
xG|T_|?
//打印回应的头信息 U1!#TD)@
public void logResponseHead(HttpURLConnection con) W-UMX',0zS
{ 0`D` Je<t
for(int i=1;;i++) UBZ37P
{ 4`M7 3k0
String header=con.getHeaderFieldKey(i); 8\H*Z2yF+
if(header!=null) ^}PG*h|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Ub_!~tb}?
Utility.log(header+" : "+con.getHeaderField(header)); jqeR{yo&0b
else 8uZM%7kI6+
break; uz%<K(:Ov
} H/?@UJ5m
} =]swhF+l-
1;8%\r[|5^
l}jC$B`5
public void splitterStop() g;n6hXq4
{ h%*@82DKK
bStop = true; Z,Z4Sp
} Nm.G,6<J
9z9\pXFQ
N R0"yJV>
} w28&qNha
_yN&+]c
#q mv(VB4
/* yRyUOTK
**FileAccess.java FMNT0
*//文件访问(定位，写) e\7AtlW"
package NetFox; V=cJdF
import java.io.*; .X](B~\!
]H$Trf:L
LuE0Hb"S8
public class FileAccessI implements Serializable{ nQaryL
?;xL]~Q~1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RE%25t|
RandomAccessFile oSavedFile; gCL?{oVU
long nPos; vKFEA7
IDK~ (t
R}E$SmFg
public FileAccessI() throws IOException -SlAt$IJ
{ O/b1^ Y
this("",0); @=NTr
} n3" @E<rW
"%rzL.</
'TO/i:{\
public FileAccessI(String sName,long nPos) throws IOException lKBI3oYn
{ E@J}(76VS
oSavedFile = new RandomAccessFile(sName,"rw"); 9 K~X+N\
this.nPos = nPos; .$U=ngj\t
oSavedFile.seek(nPos); OD6dMql
} u$rSM0CJ
oEJxey]B7
AvZOR
public synchronized int write(byte[] b,int nStart,int nLen) W_bA.zT{
{ r*kz`cJ
int n = -1; qS/ 'Kyp_
try{ eHc.#OA&
oSavedFile.write(b,nStart,nLen); )CoJ9PO7
n = nLen; q-r5zGI
} jP31K{G?
catch(IOException e) ow4|GLU^;
{ V(=3K"j
e.printStackTrace (); *(o^w'5
} tpQ8 m(
j)mi~i*U
"Z#MR`;&29
return n; Mi<}q@]e
} {4B7a6
3^`.bm4 ^
5 J 7XVe>
} GXwQ )P5]
GiKmB-HO
M5`wfF,j
/* &`}ACTY'P
**SiteInfoBean.java -ze@~Z@
*/ 6#Bg99c
package NetFox; 4`p[t;q
bJB*w
ksV^Y=]
public class SiteInfoBean { Tl S904'
QuBaG<
/jN&VpDG
private String sSiteURL; //Site's URL *]e9/f
private String sFilePath; //Saved File's Path $*;ke5Dm4
private String sFileName; //Saved File's Name NBO&VYs|
private int nSplitter; //Count of Splited Downloading File 24I~{Qy
fYzZW
x<>In"QV
public SiteInfoBean() lt|UehJF
{//nSplitter的缺省值为5 j12khp?
//default value of nSplitter is 5 _j?/O)M c
this("","","",5); q&V=A[<rz
} G;;iGN
5uD'Kd$H
ZZU"Q7`^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) F}4jm,w
{ IfpFsq:
sSiteURL= sURL; pd oCV
sFilePath = sPath; Zl7m:b2M
sFileName = sName; 0 hS(9y40
this.nSplitter = nSpiltter; YojYb]y+j
[(/IV+
"hXB_73)V
} :a y-2
`KJBQK
q/^&si
public String getSSiteURL() I~NQt^sg
{ -,}ppTG
return sSiteURL; ewv[nJD$
} qY%{c-aMA
*m`KY)b=l
&#qy:
public void setSSiteURL(String value) x)!NB99(tC
{ a%)-iL X8&
sSiteURL = value; ?#_]Lzn'
} MYF6tZ*
U#1,]a\
9|RR;k[
public String getSFilePath() w65D;9/;
{ H| 1O>p&
return sFilePath; Z}4 `y"By
} :s`\jJ
Ae 3:"
1VC:o]$
public void setSFilePath(String value) mo- Y %
{ [p# }=&d
sFilePath = value; %#,EqN
} ds"q1
Q`7.-di
O6$d@r;EK]
public String getSFileName() %wuD4PRK
{ {@w!kl~8
return sFileName; ~kW[d1'c
} o7;#B)jWS
Kt3]r:&J
8RJ^e[?o(
public void setSFileName(String value) y,QJy=?
{ t\%gP@?
sFileName = value; y}t1r |p
} WVfwt.Y
:7-2^7z)
#N'W+M /
public int getNSplitter() 7r4|>F
{ -*T<^G;rK
return nSplitter; HM(S}>
} w`$M}oX(
%}=:gF
1SGLA"r
public void setNSplitter(int nCount) [|!A3o
{ wfXm(RYM
nSplitter = nCount; at-+%e
} k6?;D_dm
} n$oHr
',Q|g^rF]
?\.aq p1B
/* shAoib?Kw:
**Utility.java {5, ]7=]
*/ )Z0bMO<
package NetFox; :ENdF `nC
ZcLW8L
EDf"1b{PX
public class Utility { AYP*J
9cwy;au
e: aa
public Utility() v{[:7]b_=
{ Fb0r(vQ^
GWvw<`4
y`|86` Y
} 5u89?-UD
qTuQ]*[-
//线程睡眠 !F|#TETrt
public static void sleep(int nSecond) y k{8O.g
{ Ump$N#
try{ W Y]
Thread.sleep(nSecond); QK`5KB(k'
} -/'_XR@1
catch(Exception e) 45aUz@
{ DQ*T2*L
e.printStackTrace (); =+z+`ot
} ^tTASK
} F!_8?=|
bQlvb
//日志 qbsmB8rh
public static void log(String sMsg) rV_i|
{ [`4
System.err.println(sMsg); xk*&zAt
} $Vp*,oRL
!y\r.fm!A
cTJi8f=g
public static void log(int sMsg) TKe\Bi
{ YT`,f*t
System.err.println(sMsg); L~+/LV
} 4^Y{ BS fF
} 0H/)wy2ym
CBr(a'3{Z
2<FEn$n[
/* dM=45$\q
**TestMethod.java mPL0s
*/ HSk_'g(\0
package NetFox; lHUd<kEC
7 'q *(v
({OQ JBC
public class TestMethod { Uc;~q-??#
:N^+!,i
Yu$QL@
public TestMethod() OUk"aAo
{ ///xx/weblogic60b2_win.exe ?KtF!:_C
try{ @V&c=8)8
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Rb!y(&>v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O joa3
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,gpZz$Ef(
fileFetch.start(); 45?%D}
} r3B}d*v
catch(Exception e){e.printStackTrace ();} u4h0s1iI
L^jjf8_
U`aB&[=$
} 5-hnk' ~
PjD9D.
#;yxn.</
public static void main(String[] args) B[k=6EU8k
{ uGv|!UQw
new TestMethod(); 9=mc3m:Tb(
} =C2KHNc
} gYCr,-_i
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