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)); <9=9b_z
} {QBB^px
for(int i=0;i<nEndPos.length-1;i++) x}U8zt)yD3
{ ze_{=Cv&Y
nEndPos = nStartPos[i+1]; Wv__ wZ
} `28};B>
nEndPos[nEndPos.length-1] = nFileLength; %}86D[PF
} G*S|KH
} B!gGK|8
$F.([?)k?
ELh8ltLY
//启动子线程 -",=G\XZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; y%sroI('y
for(int i=0;i<nStartPos.length;i++) {k4CEt;
{ r'CM
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r1ws1 rr=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), wU#F_De)R:
nStartPos,nEndPos,i); k>dsw:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ^gVT$A
fileSplitterFetch.start(); 8Qh#)hiW!
} $Vc~/>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ut>4U'.H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); v7%X@j]ji
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t9&cE:n
nEndPos = " + nFileLength); |AlR^N
// fileSplitterFetch[nPos.length-1].start(); yNm:[bOER
Z5c~^jL$-
/h v4x9
//等待子线程结束 k3+e;[My+
//int count = 0; >7!6nF3x,
//是否结束while循环 )s1Ib4C
boolean breakWhile = false; K:'q>D@
}M1sksk5
ZEYgK)^
while(!bStop) |F.)zC5{
{ 7?B.0>$3>V
write_nPos(); ,!V]jP)
Utility.sleep(500); @&D?e:|!U
breakWhile = true; ;> m"x
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for(int i=0;i<nStartPos.length;i++) [D5t{[i
{ 7_2kDDW0
if(!fileSplitterFetch.bDownOver) <foCb%$(?
{ LqdY Qd51
breakWhile = false; j)t+jcMUI
break; & cNy
} Mv c`)_Md
} pfx3C*
if(breakWhile) 0l;<5
break; H+ h07\? %
@!&}}"<
*9)SmSs
//count++; b3wM;jv
//if(count>4) {JV@"t-X3"
// siteStop(); "EU{8b
} IVr 2y8K
>NB?&|
%4\OPw&
System.err.println("文件下载结束！"); 9WJz~SP+vR
} E~<`/s
catch(Exception e){e.printStackTrace ();} IrMl:+t\
} RE.r4uOJg
9Lh|DK,nV/
X0-IRJ[
//获得文件长度 dD<fn9t
public long getFileSize() TO2c"7td
{ v^ d]rSm
int nFileLength = -1; Jc)^49Rf
try{ U/lM\3v/e
URL url = new URL(siteInfoBean.getSSiteURL()); Y!6/[<r$~k
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g'];Estb~
httpConnection.setRequestProperty("User-Agent","NetFox"); mAk{"65V
.qk]$LJF7
eMRar<)+#*
int responseCode=httpConnection.getResponseCode(); `.y}dh/+0W
if(responseCode>=400) d--y
{ x.1-)\
processErrorCode(responseCode); !ZDzEP*
return -2; //-2 represent access is error m\/ Tj0e
} :S$l"wrh\
a?yMHb{F
yT{8d.Rh
String sHeader; 2iu_pjj
~x{.jn
{_RWVVVe
for(int i=1;;i++) 6z,&i
{ `:'w@(q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); lyCW=nc
//Utility.log(in.readLine()); y/V%&.$o=
sHeader=httpConnection.getHeaderFieldKey(i); GRy-+#,b"
if(sHeader!=null) =66Nw(E.
{ E&Qi@Ty
if(sHeader.equals("Content-Length")) pj?XLiM54%
{ 0?WcoPU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +h2eqNr
break; -/]W+[
} t>B^q3\q?
} zo;^m|
else ?j^=u:<
break; ]a2W e`
} C@N1ljXJT
} Q4t(@0e}
catch(IOException e){e.printStackTrace ();} 8 i&_Jgmr
catch(Exception e){e.printStackTrace ();} Y-ux7F{=z
+.RKi!
]4+s$rG
Utility.log(nFileLength); PL{Q!QJK'
74<!&t
PNW \*;j
return nFileLength; 7^}Ll@
} /S:F)MO9
yBLK$@9
7=@jARW&
//保存下载信息（文件指针位置） cNzt%MjP
private void write_nPos() (]/9-\6(#
{ bbxLBD'
try{ .I3?7
output = new DataOutputStream(new FileOutputStream(tmpFile)); bYe;b><G
output.writeInt(nStartPos.length); W~_t~Vg5
for(int i=0;i<nStartPos.length;i++) 5q@LxDy,b
{ "i:T+#i({O
// output.writeLong(nPos); %hlspI(J
output.writeLong(fileSplitterFetch.nStartPos); P#v*TD'
output.writeLong(fileSplitterFetch.nEndPos); 3Q/#T1@
} B*!WrB:s
output.close(); 4YZS"K'E
} zb6ju]2
catch(IOException e){e.printStackTrace ();} O7']
catch(Exception e){e.printStackTrace ();} @{h?+ d
} %7Kooq(i
xr0haN\p"
$o@R^sJ
//读取保存的下载信息（文件指针位置） +Taa!hfys
private void read_nPos() R E1/"[t
{ 9iN.3/T8
try{ m?s}QGSka
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); # N~,F@t
int nCount = input.readInt(); w",? Bef
nStartPos = new long[nCount]; G ;?qWB,
nEndPos = new long[nCount]; Lw1T 4n
for(int i=0;i<nStartPos.length;i++) 4Z[V uQng
{ K[ .JlIP
nStartPos = input.readLong(); ,n2i@?NHZ
nEndPos = input.readLong(); -#-p1^v}
} 4!`bZ`_Bw
input.close(); \EbbkN:D
} #G9 adK5
catch(IOException e){e.printStackTrace ();} 57F%j3.|/
catch(Exception e){e.printStackTrace ();} vUC!fIG
} /R X1UQ.s
df+t:a
P`U<7xF~
private void processErrorCode(int nErrorCode) NV4g~+n
{ PIcrA2ll
System.err.println("Error Code : " + nErrorCode); 2EQ6J
} 0;sRJ
8GJdRL(
.AV)'j#6P
//停止文件下载 F?Ju??O
public void siteStop() 89o)M5KQ
{ 'NZGQebK
bStop = true; %Qn(rA@9
for(int i=0;i<nStartPos.length;i++) "a1O01n
fileSplitterFetch.splitterStop(); Fb2%!0i
&R+#W
jdevat,&u
} j-]&'-h}#
} T0j2a&Pv
//负责部分文件的抓取 OLq 0V3m
**FileSplitterFetch.java B68H&h]D#'
*/ 4{9d#[KW
package NetFox; >5~7u\#9
]TO/kl/
}:iBx
import java.io.*; NTs;FX~g[
import java.net.*; nbofYI$rd&
t$^l<ppQ
D)='8jV7
public class FileSplitterFetch extends Thread { 0Flu\w/+P
x)5V.q
kL@Wb/K JP
String sURL; //File URL dOa!htx]
long nStartPos; //File Snippet Start Position S_J :&9L
long nEndPos; //File Snippet End Position "YFls#4H-
int nThreadID; //Thread's ID h?@G$%2
boolean bDownOver = false; //Downing is over )tZ`K |
boolean bStop = false; //Stop identical 3bC yTZk
FileAccessI fileAccessI = null; //File Access interface }{7e7tW6
#*q2d
s #:%x#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c yQ(fIYl
{ HgJb4Fi
this.sURL = sURL; 'TN)Lb*
this.nStartPos = nStart; }|8*sk#[
this.nEndPos = nEnd; g=]&A
nThreadID = id; g;F"7 ^sg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }4jC_ZAupt
} ty1fcdFZM
#S QXTR
5#:pT
public void run() lHBI
{ O]u",J5
while(nStartPos < nEndPos && !bStop) fhp)S",
{ RcY[rnI6
T)u4S[ &
s(@h 2:j
try{ wV<7pi
URL url = new URL(sURL); &R$Q\,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kv|,b
httpConnection.setRequestProperty("User-Agent","NetFox"); _ P ,@
String sProperty = "bytes="+nStartPos+"-"; ESQ!@G/n
httpConnection.setRequestProperty("RANGE",sProperty); O?K./So&
Utility.log(sProperty); Wz=OSH7"f
u,i]a#K
4~?2wvz G4
InputStream input = httpConnection.getInputStream(); .{dE}2^
//logResponseHead(httpConnection); gzfbzt}?
H9"= p
oC dGQ7G}
byte[] b = new byte[1024]; \4~AI=aw,T
int nRead; HR{s&ho
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6o}V@UzqV
{ #0y<a:}R
nStartPos += fileAccessI.write(b,0,nRead); c cG['7
//if(nThreadID == 1) f>iuHR*EXB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7s>a2
} r7z6___
G\Hq/4
vP]9;mQ
Utility.log("Thread " + nThreadID + " is over!"); ^KHLBSc:
bDownOver = true; -Q[g/%
//nPos = fileAccessI.write (b,0,nRead); =:$) Z
} z4Oo@3$\R
catch(Exception e){e.printStackTrace ();} IlZu~B9c
} IvU{Xm"qB
} N)OCSeh
#qL9{P<}
n E:'Zxj
//打印回应的头信息 (9.yOc4
public void logResponseHead(HttpURLConnection con) cK}Pf+r>
{ ,7/ _T\d<
for(int i=1;;i++) hTS|_5b
{ ]mkJw3
String header=con.getHeaderFieldKey(i); `"<2)yq?
if(header!=null) p]f&mBO*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MQw9X
Utility.log(header+" : "+con.getHeaderField(header)); u^Sv#K X
else 8]*Q79
break; jPwef##~7
} Z.jCera.
} wa?+qiWnrl
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nk08>veG
public void splitterStop() (KF7zP
{ c cr" ep
bStop = true; 3"i%{
} z[#6-T &
70`M,``
+{>.Sk'$
} b.Su@ay@(^
oI$V|D3 9
RK)l8c}
/* HYIRcY
**FileAccess.java ~{QEL2
*//文件访问(定位，写) [b`$\o'-
package NetFox; q6)N*?
import java.io.*; NG-`ag`s
YRa4W.&Yn
Sr7@buF
public class FileAccessI implements Serializable{ m!!;/e?yx
gE=Wcb!
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /#\?1)jCK
RandomAccessFile oSavedFile; Y@:3 B:m#
long nPos; m.146
m^0A?jBrR
Qv!rUiXq
public FileAccessI() throws IOException pGk"3.ce
{ eiB(VOJ
this("",0); Q<'@V@H
} \]a uSO
PJwEA
.HDebi
public FileAccessI(String sName,long nPos) throws IOException "o==4?*L
{ =tq7z =k
oSavedFile = new RandomAccessFile(sName,"rw"); E3tj/4:L
this.nPos = nPos; '}zT1F* p=
oSavedFile.seek(nPos); *^6k[3VY
} nOuN|q=C
2mOfsn d@
AO8:|?3S
public synchronized int write(byte[] b,int nStart,int nLen) Tg\hx>
{ @ V5S4E
int n = -1; (\uAAW"
try{ 3GINv3_
oSavedFile.write(b,nStart,nLen); x 8M#t(hw
n = nLen; 0~.)GG%R>D
} z (#Xca
catch(IOException e) |+mOH#Aty
{ 5:_~mlfi
e.printStackTrace (); bXm:]?
} g`{Dxb,t
0$?qoS
6m\*]nOy4
return n; <[FS%2,0mb
} {6YxN&
hgif]?:C<
af^@ .$ |
} Yoe les-
nO:HB.&@
CH#kvR2
/* ZK!4>OuH`
**SiteInfoBean.java / (.'*biQ
*/ /J8o_EV
package NetFox; ndB@J*Imu
S#hu2\9D,
gm}C\q9
public class SiteInfoBean { FBbm4NB
&BTfDsxAK
B~BUWWMfp
private String sSiteURL; //Site's URL .yG8B:7N2
private String sFilePath; //Saved File's Path {;;eOxOP|
private String sFileName; //Saved File's Name \hu':@}
private int nSplitter; //Count of Splited Downloading File 8}J(c=4Gk
.8%vd
?^eJ:
public SiteInfoBean() f5N<3m=
{//nSplitter的缺省值为5 w[M5M2CF
//default value of nSplitter is 5 Hq79/wKj
this("","","",5); QZ:v
} ;7)OSGR
AV9:O{
P)4x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) V9gVn?O0
{ @eA %(C
sSiteURL= sURL; mnQal>0~
sFilePath = sPath; e$x4Ux7*"
sFileName = sName; 0yKwH\S
this.nSplitter = nSpiltter; '%3u%;"
?F!W#
/S/tE
} !+%Az*ik
MQjG<O\
EOofa6f&l
public String getSSiteURL() +6wx58.B&
{ 6@i|Kw(:
return sSiteURL; SG1&a:c+.
} es{cn=\s
<)=3XEcb
|:\$n}K
public void setSSiteURL(String value) `f2W;@V0
{ 54;l*}8Hl
sSiteURL = value; t.gq5Y.[
} PV?1g|tYv
eR(\s_`
sf<Q#ieTxY
public String getSFilePath() Ixyvn#ux)
{ Bd/} %4V\@
return sFilePath; N,h1$)\B#
} ?hP<@L6K
\IO$+Guh
{c&qB`y<.
public void setSFilePath(String value) 5F% h>tqh
{ jM{(8aUG
sFilePath = value; t00\yb^vJ8
} |C&%S"*+D
U#OWUZ
BYkVg2D(
public String getSFileName() m j'"Z75
{ ^mS.HT=X
return sFileName; EKV+?jj$
} ^cfkP(Y3kx
-ryDsq
N`y}Gs
public void setSFileName(String value) "u .)X3
{ yBJ/>SAcG
sFileName = value; ^=aml
} Tz+HIUIxF
$,xtif0
-[i40 1
public int getNSplitter() ~| 4U@
{ p} t{8j>
return nSplitter; V=G b>_d
} pil0,r $D
)< &B&Hp
GhSL%y
public void setNSplitter(int nCount) 7yc9`j}]
{ *%P>x}6w3
nSplitter = nCount; [8B tIv
} pCB 5wB
} :w?:WH?2L
vLi/'|7
.5jnKU8NF
/* >X-ed
**Utility.java *u:;:W&5y
*/ [ t>}SE
package NetFox; aYv'H
UE}8Rkt
Jdk3) \
public class Utility { bIvJs9L
uzzWZ9Tv
yv6Zo0s<J
public Utility() mq|A8>g
{ }1X11+/W
Wto@u4
`'A(`. CL
} CF4Oh-f
i?1js! 8
//线程睡眠 qK9L+i
public static void sleep(int nSecond) j`[yoAH
{ kR`6s
try{ D:ql^{~
Thread.sleep(nSecond); -dc"N|.
} lOWB^uS%
catch(Exception e) 9^#zxmH)
{ pXpLL_
e.printStackTrace (); JxMyeo%gv
} -z>Z0viA
} _rWM]
c5T~0'n
//日志 ShEaL&'J
public static void log(String sMsg) _G-bL;
{ kz$6}&uk
System.err.println(sMsg); Z=e[ !c
} Qwp\)jVi
Zh@4_Z9n!
]noP
public static void log(int sMsg) Et@=Ic^E
{ rA1zyZlz
System.err.println(sMsg); ^5FJ}MMJf
} ,Do$`yO+
} 2m)kyQ
Y1yvI
$~w@0Yl
/* 34+)-\xt:
**TestMethod.java VrnK)za*H
*/ )$9C`d[
package NetFox; ecSdU>
.Y^d9.
.NNcc4+
public class TestMethod { HiS,q0
9:K
#um1?V
public TestMethod() 3;t@KuQ66
{ ///xx/weblogic60b2_win.exe Q)%8NVs
try{ #LrCx"_&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); %(dV|,|v
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Gct&}]3pm
SiteFileFetch fileFetch = new SiteFileFetch(bean); 0%qctZy
fileFetch.start(); YP .%CD(K
} VAF:Z
catch(Exception e){e.printStackTrace ();} R.T?ZF
C,VqT6E<
O_s9
} b Q9"GO<X
Us@ {w`T
Gg3?2h"d
public static void main(String[] args) lo>-}xd
{ 9m#H24{V'
new TestMethod(); 9+N._u
} =JySY@?9
} /RXk[m-
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