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)); :7p0JGd
} m}0US;c#f
for(int i=0;i<nEndPos.length-1;i++) qie7iE`o
{ YE&"IH]lF
nEndPos = nStartPos[i+1]; La?q>
} c;e-[F7
nEndPos[nEndPos.length-1] = nFileLength; Ld? tVi
} )F&@ M;2p'
} =If% m9
C1P{4 U
7P9n. [
//启动子线程 Vn? %w~0!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I"@X~Y7}
for(int i=0;i<nStartPos.length;i++) y|q4d(P.
{ d9|dHJf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #/@U|g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ([UuO}m-
nStartPos,nEndPos,i); AL! ^1hCF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c&)H
fileSplitterFetch.start(); Jl&bWp^3
} j11\t
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,Ihuo5>/z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [6BLC{2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /7*jH2
nEndPos = " + nFileLength); lO8.Q"mxo
// fileSplitterFetch[nPos.length-1].start(); F1R91V|
5/DTE:M<
k);z}`7
//等待子线程结束 8,YF>O&
//int count = 0; wq_c^Ioy
//是否结束while循环 &T]+g8''
boolean breakWhile = false; b>E%&sf
VP\HPSp
rB?u.jn0T
while(!bStop) E!Hq%L!/
{ xq=+M!V
write_nPos(); F/ 2@%,2n
Utility.sleep(500); hSaS2RLF
breakWhile = true; 9:A>a3KOH
1O45M/5\o
I!jSAc{
for(int i=0;i<nStartPos.length;i++) M! gX4
{ mc|T}B
if(!fileSplitterFetch.bDownOver) "$+naY{w
{ '0X!_w6W
breakWhile = false; Ql%7wrK
break; F^_d8=67h
} /V~L:0%
} mLk@&WxG
if(breakWhile) H#k"[eZ
break; 9 f-T>}
swG^L$r`
xj{X#[q):
//count++; J[YA1
//if(count>4) v6oPAqj,r
// siteStop(); riZFcVsB
} G6JyAC9j
Q'JEDH\
/}2 bsiJT
System.err.println("文件下载结束！"); 0NfO|l7P
} )]J I Q"rR
catch(Exception e){e.printStackTrace ();} 5h1!E
} C-qsyJgZy
>tr?5iKxc
"+_]N9%)
//获得文件长度 2F!K }aw
public long getFileSize() cAyR)Y!I
{ uByF*}d1
int nFileLength = -1; vIU+ZdBw
try{ r{)d?Ho=
URL url = new URL(siteInfoBean.getSSiteURL()); p$f#W
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (J.(Fl>^
httpConnection.setRequestProperty("User-Agent","NetFox"); #lltXqvD?
;VK;_d
Z/q%%(fh 0
int responseCode=httpConnection.getResponseCode(); >1pD'UZIy7
if(responseCode>=400) ?*}76u
{ MP[v 9m@
processErrorCode(responseCode); \*LMc69
return -2; //-2 represent access is error n8[sR;r5f
} x@DXW(
sl6p/\_w
{,IWjt &>
String sHeader; ?MKf=!w
P)1@HDN==
\q3H#1A
for(int i=1;;i++) tyP-J4J
{ f*XF"@ZQV
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z$7YC49^
//Utility.log(in.readLine()); +Jt"JJ>%k
sHeader=httpConnection.getHeaderFieldKey(i); Cb=r8C
if(sHeader!=null) Ep5lmzg
{ k%hD<_:p
if(sHeader.equals("Content-Length")) C$*`c6R
{ OOl{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wrqdQ}@(
break; m6 hA,li
} W:(:hT6`j9
} ivoPl~)J
else 82$By]Y9
break; <$?:|
} x ?^c:`.
} rA`zuYo
catch(IOException e){e.printStackTrace ();} M|n)LyL
catch(Exception e){e.printStackTrace ();} |]GEJUWtCd
/4_}wi\
Jk{>*jYk`
Utility.log(nFileLength); ,<EmuEw |
Lj~lfO
7e8hnTzl8<
return nFileLength; IE_@:]K}Ja
} '/sc `(`:0
m9L+|r
H~ks"D1
//保存下载信息（文件指针位置） M<ad>M
private void write_nPos() Ku&(+e
{ ,1~Zqprn
try{ //J:p,AF
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]G1j\wnF
output.writeInt(nStartPos.length); t<`ar@}
for(int i=0;i<nStartPos.length;i++) HhqqJEp0
{ DVB:8"Bu
// output.writeLong(nPos); (S2<6Nm8
output.writeLong(fileSplitterFetch.nStartPos); $hKgTf?
output.writeLong(fileSplitterFetch.nEndPos); \&TTe8
} E32z(:7M
output.close(); `/HygC6
} 3_h%g$04s
catch(IOException e){e.printStackTrace ();} PA,j;{,(b
catch(Exception e){e.printStackTrace ();} qWanr7n]@
} ?5(L.XFm
9txZ6/
Ys<wWfW
//读取保存的下载信息（文件指针位置） QlXy9-oJ"
private void read_nPos() Rp@u.C<
{ htF&VeIte
try{ (vI7qD_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ce0I8B2y
int nCount = input.readInt(); I* bjE'
nStartPos = new long[nCount]; 61mQJHl.
nEndPos = new long[nCount]; }K*ri
for(int i=0;i<nStartPos.length;i++) PH7L#H^
{ gIRCJ=e[b
nStartPos = input.readLong(); Q1jyetk~I
nEndPos = input.readLong(); s]I],>}RU
} 3R{-\ZMd
input.close(); ;zCHEz
} TuF:m"4
catch(IOException e){e.printStackTrace ();} B"qG-ci
catch(Exception e){e.printStackTrace ();} JfVayI=
} <;XJ::d
]!A;-m
K[ \z'9Q
private void processErrorCode(int nErrorCode) hV,3xrm?P
{ *jJ62-o
System.err.println("Error Code : " + nErrorCode); VLO>{"{'
} :?p{ga9
+]>a`~
bkM$ Qo
//停止文件下载 z N t7DK
public void siteStop() /tUl(Fp J`
{ 4/h2_
bStop = true; Gt1Up~\s
for(int i=0;i<nStartPos.length;i++) t]` 2f3UO
fileSplitterFetch.splitterStop(); q@\_q!
sbs"26IE
xv*mK1e
} gRFC n6Q
} iM9563v
//负责部分文件的抓取 V\G>e{
**FileSplitterFetch.java A]J^{h0k
*/ >u4e:/5]
package NetFox; =3T?U_u@
\ bhok
Q0--.Q=:Y
import java.io.*; ~FsUK;?
import java.net.*; kN^)6
B.WJ6.DkS
y H'\<bT
public class FileSplitterFetch extends Thread { ~"wD4Ue
nY8UJy}<oL
J~}UG]j n
String sURL; //File URL )s8r(.W
long nStartPos; //File Snippet Start Position F#PJ+W*h
long nEndPos; //File Snippet End Position ,qfa,O
int nThreadID; //Thread's ID 7*5ctc!dG
boolean bDownOver = false; //Downing is over ]lo1Kw
boolean bStop = false; //Stop identical |HA7 C
FileAccessI fileAccessI = null; //File Access interface KF'M4P
Qnw$=L:
J)G3Kq5>:b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException U\ L"\N7
{ HUghl2L.<
this.sURL = sURL; l<HRD
this.nStartPos = nStart; %b?Pasf.
this.nEndPos = nEnd; &-*nr/xT
nThreadID = id; Z`*cI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $"i690
} <oO,CXF
G<z)Ydh_
@Dy.HQ~
public void run() 6Te}"t>
{ m7"f6zSo(
while(nStartPos < nEndPos && !bStop) yRznP)
{ >ob/@
cDx^}N!
Wk|z\OR(
try{ w=`z!x![/
URL url = new URL(sURL); O)Qz$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @( t:E`8
httpConnection.setRequestProperty("User-Agent","NetFox"); z(WpOD
String sProperty = "bytes="+nStartPos+"-"; e?YbG.(E9
httpConnection.setRequestProperty("RANGE",sProperty); "uCQm '
Utility.log(sProperty); lkm(3y@']A
c|R/,/
jQb D2x6(
InputStream input = httpConnection.getInputStream(); 9PJDT]
//logResponseHead(httpConnection); 1FJ[_l
Kzb@JBIF
6ZR0_v;TD
byte[] b = new byte[1024]; *I67SBt
int nRead; Ig<p(G.;}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E8i:ER $$7
{ NM@An2
nStartPos += fileAccessI.write(b,0,nRead); ) b10%n^
//if(nThreadID == 1) [*G2wP[$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Fjzk;o
} @>]3xHE6#=
@"!SU'*
q(7D8xG;F
Utility.log("Thread " + nThreadID + " is over!"); 5avO48;Vc
bDownOver = true; u\xm8}A
//nPos = fileAccessI.write (b,0,nRead); @9h#o5y q
} !`_f\
catch(Exception e){e.printStackTrace ();} =dBrmMh
} HWhKX:`l
} a,~P_B|@
m'tk#C
50&F#v%YB
//打印回应的头信息 9ojhI=:
public void logResponseHead(HttpURLConnection con) gcxk'd
{ f>dkT'4
for(int i=1;;i++) ,7P^]V1
{ !P$xh
String header=con.getHeaderFieldKey(i); \2pFFVT
if(header!=null) A232"p_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Y2-bU 7mo
Utility.log(header+" : "+con.getHeaderField(header)); >n~p1:$
else HIm, "iYk
break; S=p u
} 7Ca\ (82
} MuGg z>CV[
3.X0!M;x
qJU)d
public void splitterStop() YSo7~^1W"
{ #&83;uys
bStop = true; sK0VT"7K
} F5+_p@!i
gi'agB^
V^I/nuy
} v4_OUA>z,
h)8+4?-4I
(Fzh1#
/* lzG;F]
**FileAccess.java `HG19_Z
*//文件访问(定位，写) 4QAIQQS
package NetFox; ]Cn*C{
import java.io.*; [IFRwQ^%_O
;Ia1L{472m
|HGb.^f?
public class FileAccessI implements Serializable{ *g4Cy8$
""3m!qn#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~88 Tz+
RandomAccessFile oSavedFile; %8CT -mQ
long nPos; ,'CWt]OS'
7&V^BW
|.O!zRm
public FileAccessI() throws IOException h5rP]dbhXU
{ R.IUBw5;/
this("",0); J xm9@,
} 07Q[L'}y@
FJ~_0E#L
:$i:8lz
public FileAccessI(String sName,long nPos) throws IOException MW$H/:3
{ @:+n6
oSavedFile = new RandomAccessFile(sName,"rw"); U?fN3
this.nPos = nPos; H r^15
oSavedFile.seek(nPos); )_*a7N!
} |sqo+E
H!r Kz
=+}}Sv2
public synchronized int write(byte[] b,int nStart,int nLen) I"32[?0 (;
{ ESxC{ "
int n = -1; /~l/_Jct@G
try{ ?ZHE8
oSavedFile.write(b,nStart,nLen); ?h)3S7
n = nLen; )^f9[5ee
} %}MA5 t]o
catch(IOException e) >Ug?O~-
{ w<~<(5mM5;
e.printStackTrace (); }SMJD
} cbCE $
Fy@#r+PgWp
Kwl qi]~
return n; @y0bU*v7
} E[3FdX8
Mj B<\g>
)n}]]^Sc
} 4ZJT[zi
U++~3e@l
r` `iC5Ii
/* AqbT{,3yW
**SiteInfoBean.java c > mu)('U
*/ frmqBCVJ:
package NetFox; {8#N7(%z
`+hy#1]
Md>f
public class SiteInfoBean { `}9 1S
a|P~LMPM
B2G5hbaA
private String sSiteURL; //Site's URL Z0"&
private String sFilePath; //Saved File's Path Naf`hE9
private String sFileName; //Saved File's Name !*?(Q6
private int nSplitter; //Count of Splited Downloading File O:,2OMB}B`
a\&(Ua
Ukx/jNyYv
public SiteInfoBean() tC?Aso
{//nSplitter的缺省值为5 85%Pq:E
//default value of nSplitter is 5 u1;e*ty
this("","","",5); X(!AI|6Bt
} VX!Y`y^a
~*mOt7G
ci,o8 [Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (Gi+7GMV'
{ g\qL}:
sSiteURL= sURL; zY+t,2z
sFilePath = sPath; | 3N.5{
sFileName = sName; sm2p$3v
this.nSplitter = nSpiltter; xS~yH[k
mI7rx`4H
=nvAOvP{?
} b#p~F}qT
S:p.W=TAB
!$p2z_n$@.
public String getSSiteURL() uXQ7eXX
{ I|F~HUzA"
return sSiteURL; /OhaERv
} ]Z.<c$
m]0^
!bZhj3.
public void setSSiteURL(String value) piYws<Q
{ vLnq%@x
sSiteURL = value; O^X[9vrW
} m~Y'$3w
' 1P=^
xm}q6>jRV
public String getSFilePath() vbRrk($`
{ /$FXg;h9$
return sFilePath; 4-]Do?
} 5vs`uUzr
b`h%W"|2L
]]J#7L#
public void setSFilePath(String value) h/ LR+XX!
{ iot.E%G
sFilePath = value; RwAbIXG{0
} Yg=E@F
Z:_m}Ya|
]RH=s7L
public String getSFileName() ><;l:RGK|
{ GOYn\N;V2
return sFileName; )Lc<;=w'9
} 85r)>aCMn
f MY;
).0V%}>
public void setSFileName(String value) *? K4!q'
{ /S7+B]
sFileName = value; 1<LC8?wt
} %_B:EMPd
, @%C8Z
-H1"OJ2aF
public int getNSplitter() &YT_#M
{ ?ID* /u|X
return nSplitter; N?qIpv/a.
} hmK8jl<6
j+_S$T8w
\6`v.B&v
public void setNSplitter(int nCount) S2J#b"Y
{ CrnB{Z4L
nSplitter = nCount; G$;>ueM
} QD$}-D[
} X'V+^u@W
hlAR[]
TK;\_yN
/* RGT_}ni
**Utility.java 8w)e/*:j
*/ y#]}5gJ
package NetFox; r?64!VS;
Xtci0eS#V
)^t!|*1LA
public class Utility { Ms.PO{wb
P['X<Xt8
IXGW2z;
public Utility() [ 3$.*
{ tO?21?AD D
7*zB*"B'1t
qTyg~]e9(
} KK:N [x
u$WBc\j
//线程睡眠 7d3'CQQ4
public static void sleep(int nSecond) '"oo;`g7
{ >?S\~Y
try{ x Z|&/Ci
Thread.sleep(nSecond); =y?#^
} WwW"fkv
catch(Exception e) NNwc!x)*
{ (N,nux(0k
e.printStackTrace (); )r ULT$;i@
} WI,40&<
} .W!tveX8-
uVN.=
//日志 >HE,'
public static void log(String sMsg) 4Z*|Dsw
{ riID,aut
System.err.println(sMsg); hZ!oRWIU%G
} N g58/}zO
y&7YJx
.j:i&j(
public static void log(int sMsg) joe9.{
{ 2*+3RrJ
System.err.println(sMsg); JYPxd~T/-
} 2bWUa~%B
} -r!42`S
!d\t:0;
^rL,&rk
/* <#>Oy&E
**TestMethod.java ?p(kh^z
*/ =KV@&Y^x4
package NetFox; ?~!tM}X0:3
u0xQ;BQ
-<6v:Z
public class TestMethod { ]K7`-p~T
x7f:F.
!;i*\ a
public TestMethod() 5!~!j "q
{ ///xx/weblogic60b2_win.exe S0F@#mSQ?
try{ fVYiwE=F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d5Qd'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `"B^{o
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y=9j2 ]t
fileFetch.start(); 4KE)g
} UIn^_}jF`
catch(Exception e){e.printStackTrace ();} ?gLAWz
=qw&dwIQ
S9J5(lYv~N
} oB4#J*
.vK.XFZ8R
qh$X^%g
public static void main(String[] args) *.8JP
{ _D-5}a"
new TestMethod(); 3g;T?E
} YX_vv!-]
} A]j}'
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