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)); \#~~,k 6f
} gNe{P~ $=
for(int i=0;i<nEndPos.length-1;i++) !L>'g
{ BXLhi(.s
nEndPos = nStartPos[i+1]; |nMbf
} j^:\a\-1
nEndPos[nEndPos.length-1] = nFileLength; RkC?(p
} aiUn bP
} &XN*T.Y`
[NC^v.[1[
5E~][. d
//启动子线程 V$^x]z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; wxvt:==
for(int i=0;i<nStartPos.length;i++) T,jxIFrF
{ ,ad~6.Z_)
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0wxQ,PI1'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "<bL-k*H)
nStartPos,nEndPos,i); IHf A;&b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -3haLdRk6
fileSplitterFetch.start(); 0]NjsOU=
} A9F&XF7{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &>sG xK
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Jtc?p{
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", sp'q=^t
nEndPos = " + nFileLength); '(I"54W
// fileSplitterFetch[nPos.length-1].start(); B>-Iv_
} %rF}>$A
0p&:9|'z
//等待子线程结束 ])0&el3-
//int count = 0; >>K) 4HYID
//是否结束while循环 yBq4~b~[
boolean breakWhile = false; P0UMMn\-#
awo=%vJ&
| u36-
while(!bStop) mrk Q20D
{ 3^wJ4=^
write_nPos(); 6lsU/`.
Utility.sleep(500); SlsMMD
breakWhile = true; k' pu%nWN
h&.9Q{D
w QwY_ _
for(int i=0;i<nStartPos.length;i++) N4'b]:`n
{ vy6NH5Q
if(!fileSplitterFetch.bDownOver) hF!yp7l;
{ p8o%H-Xk
breakWhile = false; }?8KFe7U
break; M[HPHNsA&
} $ 'HiNP {c
} {h|3P/?7
if(breakWhile) ;%Jp@'46
break; QMHeU>
m,qU})
69\0$O
//count++; !=I:Uc-Y
//if(count>4) pO=bcs8Z
// siteStop(); ,tmo6D62
} I0GL/a4s
B% BO
kRZ(
System.err.println("文件下载结束！"); !X*L<)=nh
} rDm>Rm=
catch(Exception e){e.printStackTrace ();} Ab8~'<F$B
} G }TT-
.r[J} O"
w{#%&e(q"
//获得文件长度 6R dfF$f
public long getFileSize() ()3+!};
{ T\. 8og
int nFileLength = -1; E=HS'XKu[K
try{ }MuXN<DDb
URL url = new URL(siteInfoBean.getSSiteURL()); fJC)>doM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Mp"] =
httpConnection.setRequestProperty("User-Agent","NetFox"); Ypha{d
c$@,*c 0n
li,kW`j+t
int responseCode=httpConnection.getResponseCode(); eAm7*2
if(responseCode>=400) &Lk@Xq1
{ Sg')w1
processErrorCode(responseCode); 32YE%
return -2; //-2 represent access is error {tF=c0Z
} e7pN9tXGf
B_c(3n-"
(;C_>EL&u
String sHeader; \MK)dj5uUJ
.#rI9op
'HPw5 L
for(int i=1;;i++) z}OY'}sk8
{ &!KJrQ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); # |w,^tV
//Utility.log(in.readLine()); p^\>{
sHeader=httpConnection.getHeaderFieldKey(i); JnV$)EYi
if(sHeader!=null) - stSl*
{ //K]zu
if(sHeader.equals("Content-Length")) !Z<Z"R/
{ w[:5uo(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ra$_#HY
break; tJ2l_M^
} 69O?sIk
} 2zArAch
else 8t9sdqM/C
break; \`|,wLgH
} &hjrJ/'^
} ax7ub
catch(IOException e){e.printStackTrace ();} ft:/-$&H
catch(Exception e){e.printStackTrace ();} WNlWigwYl
ls 'QfJm
C@hnT<e
Utility.log(nFileLength); 6Q>:g"_
;2#HM^Mu
ax'Dp{Q
return nFileLength; LTBqXh
} t~,!a?S7
:,]%W $f=
tul5:}x3
//保存下载信息（文件指针位置） - uliND
private void write_nPos() |~#!e}L(
{ ''v_8sv
try{ h#;fBQ]
output = new DataOutputStream(new FileOutputStream(tmpFile)); \AkeC6[D
output.writeInt(nStartPos.length); AO>K 6{
for(int i=0;i<nStartPos.length;i++) ;y4 "wBX
{ [4PG_k[uTJ
// output.writeLong(nPos); m'z<d
output.writeLong(fileSplitterFetch.nStartPos); l&;#`\s!V
output.writeLong(fileSplitterFetch.nEndPos); k3^S^Bv\
} sL+/Eeb` c
output.close(); Tet,mzVuu
} PNg,bcl
catch(IOException e){e.printStackTrace ();} cnhYrX^
catch(Exception e){e.printStackTrace ();} Kax85)9u
} b`18y cVME
i#(T?=VPcy
cz&FOP+!
//读取保存的下载信息（文件指针位置） &ATjDbW*(
private void read_nPos() t4F1[P
{ *gVRMSrx4
try{ ]U'KYrh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A3M)yWq
int nCount = input.readInt(); J}%&;uv
nStartPos = new long[nCount]; tw\/1wa.
nEndPos = new long[nCount]; H[!by)H
for(int i=0;i<nStartPos.length;i++) *<s|WLMG
{ 611:eLyy&l
nStartPos = input.readLong(); spd>.Cm`
nEndPos = input.readLong(); won%(n,HT
} a?\ Au
input.close(); ECU:3KH>MF
} Y/)>\
catch(IOException e){e.printStackTrace ();} WAkKbqJV
catch(Exception e){e.printStackTrace ();} Sf lHSMFw
} FW=oP>f]w
:);GeZ
95?$O~I
private void processErrorCode(int nErrorCode) 7lf* vqG
{ e"[o2=v;5
System.err.println("Error Code : " + nErrorCode); sq-[<ryk
} vKol@7%N
9M<qk si
a:v&pj+|<
//停止文件下载 G|IO~o0+
public void siteStop() W[w8@OCNf
{ ?5jkb
bStop = true; l*b3Mg
for(int i=0;i<nStartPos.length;i++) >$?$&+e}
fileSplitterFetch.splitterStop(); qZCA16
|u7vY/
9q;+ Al^Z
} rFdq \BSi
} 9m%[ y1v0
//负责部分文件的抓取 "*XR'9~7
**FileSplitterFetch.java OAR#* ~q
*/ |jO&qT]{
package NetFox; Rco#?'
s?7g3H5#0k
Abd&p N
import java.io.*; !1w=_
import java.net.*; P*)}ENY
^)D[ W(*
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public class FileSplitterFetch extends Thread { .E"hsGH9h
shjS^CP
Ef:.)!;jy
String sURL; //File URL aXhgzI5]
long nStartPos; //File Snippet Start Position x.xfMM2n
long nEndPos; //File Snippet End Position ~X*)gS-=
int nThreadID; //Thread's ID mp+ %@n.;
boolean bDownOver = false; //Downing is over 4}gqtw:
boolean bStop = false; //Stop identical q.g<gu]
FileAccessI fileAccessI = null; //File Access interface o!gl :izb
=K-B I
m9a(f>C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ca0~K42~
{ ZlUd^6|:3
this.sURL = sURL; A"2k,{d
this.nStartPos = nStart; OB>Pk_eQK
this.nEndPos = nEnd; gj0gs
nThreadID = id; NYm2fFPc
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q1.w8$
} y4w{8;Mh
t+|c)"\5h
.FtW$Y~y
public void run() /RIvUC1
{ cAC]%~orx
while(nStartPos < nEndPos && !bStop) Z)~.OqRw]
{ aP>%iRk'J!
)lTkqz8v
Z455g/=ye
try{ $NWXn,Y'
URL url = new URL(sURL); N3!x7J7A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2E9Cp
httpConnection.setRequestProperty("User-Agent","NetFox"); qfd/t<?|D
String sProperty = "bytes="+nStartPos+"-"; Cb%?s
httpConnection.setRequestProperty("RANGE",sProperty); oe=^CeW"
Utility.log(sProperty); PxhB=i!'$
kXFgvIpg<
1 `hj]@.]
InputStream input = httpConnection.getInputStream(); /EZF5_`bT
//logResponseHead(httpConnection); MN}@EQvW==
&}_E~jKK
4onRO!G,
byte[] b = new byte[1024]; w4\b^iJz
int nRead; f R$E*Jd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) /. k4Y
{ d3v5^5kU
nStartPos += fileAccessI.write(b,0,nRead); \tc4DS
//if(nThreadID == 1) C (L1
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); F.<sKQ&A
} l{[{pAm
R4.$9_ui
OlL FuVR
Utility.log("Thread " + nThreadID + " is over!"); ,B_Nz}\8
bDownOver = true; hX#y7m
//nPos = fileAccessI.write (b,0,nRead); 66NJ&ac
} U p=J&^.
catch(Exception e){e.printStackTrace ();} bS=aFl#
} ] lE6:^V
} 0>} FNRC
h:\WW;s[B
}1=V`N(
//打印回应的头信息 v9QR,b`n
public void logResponseHead(HttpURLConnection con) Q*u4q-DE
{ %JF.m$-
for(int i=1;;i++) !B5 }`*1D
{ kTZ`RW&0
String header=con.getHeaderFieldKey(i); ]a F,r"
if(header!=null) +Wrj%}+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,_ }
Utility.log(header+" : "+con.getHeaderField(header)); 3)b[C&`
else *p0n{F9
break; K;^$n>Y
} "#anL8
} D/[(}o(
Nj4=
-'ePx f
public void splitterStop() 9|R]Lz3PA
{ yAz`n[
bStop = true; z UN&L7D
} 8,d<&3D
^Tgu]t
K:hZ
} 5$9g4
' P5ttI#|
zg L0v5vk
/* E:'TZ4Z
**FileAccess.java /qM:;:N%j
*//文件访问(定位，写) N.R,[K
package NetFox; ?"-%>y@w
import java.io.*; ElLDSo@WvR
sx7;G^93
x$ z9:'U
public class FileAccessI implements Serializable{ !ZlBM{C
Jm0o[4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .hO) R.
RandomAccessFile oSavedFile; /E8{:>2
long nPos; Jse;@K5y
CEbZj z|
wtlIyE
public FileAccessI() throws IOException ;n1<1M>!
{ >.'rN>B+
this("",0); Ldqn<wNnI
} j_YpkKhen
a k&G=a6^
vU=+
public FileAccessI(String sName,long nPos) throws IOException O_-Lm4g?4
{ ixc~DV+@[
oSavedFile = new RandomAccessFile(sName,"rw"); G- nS0Kn:
this.nPos = nPos; %A_h!3f&
oSavedFile.seek(nPos); )lB 3U
} Ne>yFl"u
wyG7SA
6_xPk`m
public synchronized int write(byte[] b,int nStart,int nLen) JAEn 72
{ Y.FqWJP=p
int n = -1; n~`1KC4
try{ zb<YYJ]
oSavedFile.write(b,nStart,nLen); OAx5 LTd
n = nLen; `?@7T-v
} b/^i
catch(IOException e) oZVq}}R
{ nKxu8YAJe
e.printStackTrace (); YKCd:^u
} :g@H=W
,gYbi-E
NHI(}Ea|]
return n; Js{X33^Ju
} y$-;6zk\]
0_\@!#-sml
?4QX;s7
} m3Ma2jLWC
DNYJR]>
hzv4+1Wd[
/* uUy~$>V
**SiteInfoBean.java ,dyCuH!B
*/ %4
package NetFox; {|:ro!&
@ ={Hx$zL
j_w"HiNBA
public class SiteInfoBean { i6Zsn#Z7)
cviPCjM
OH+kN/Fd
private String sSiteURL; //Site's URL v2ab
private String sFilePath; //Saved File's Path Wycood*
private String sFileName; //Saved File's Name Z@i"/~B|4\
private int nSplitter; //Count of Splited Downloading File pGO=3=O
qukym3F
yv),>4_6
public SiteInfoBean() M9*#8>
{//nSplitter的缺省值为5 q-tm`t*7
//default value of nSplitter is 5 Ng=_#<
this("","","",5); :_,oD
} TAd~#jB9
<4{Jm8zJ
uC2-T5n'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 108cf~2&
{ 4xYW?s(
sSiteURL= sURL; Dej_(Dz_S
sFilePath = sPath; 0<^!<i(%
sFileName = sName; Ad%3 fvn
this.nSplitter = nSpiltter; V1h&{D\"
o$4xinK
(-e*xM m
} SAQ|1I#"/
MjjN
/);S?7u.
public String getSSiteURL() SO!|wag$
{ "bhF`,V
return sSiteURL; B_ x?s
} V DN@=/
cM|!jnKm
Tl/!Dn
public void setSSiteURL(String value) ()\=(n!J
{ 8gIf
sSiteURL = value; &xgKHbg
} r9\7I7z
_`Lv@T.
*PF}L%K(?
public String getSFilePath() v-utDQT3
{ D# Gf.c
return sFilePath; iCZuE:I1K,
} PKxI09B
YU]|N'mL2
' 5F3,/r
public void setSFilePath(String value) KFuPgp
{ ^F="'/Pq[
sFilePath = value; 9$~a&lXO5
} AuW-XK.
*hV$\CLT.
_G62E$=
public String getSFileName() 9|{t%F=-
{ x 8_nLZ
return sFileName; GxynLXWo>
} V1]QuQ{&s
Sy0-tK4
X?B\+dq
public void setSFileName(String value) ]iq2_{q
{ 9!>Ks8'.d
sFileName = value; \GP0FdpV
} .{8?eze[m
XusTU
T=W;k<P\k
public int getNSplitter() s`$YY_
{ mzGMYi*
return nSplitter; 0nu&JQ
} HB0DG<c-
Hl*V i3bQU
-(FhjIr
public void setNSplitter(int nCount) n@PXC8}
{ f [DZ
nSplitter = nCount; *u)#yEJ)
} QNcbl8@
} `z!6zo2d
!8@8
g)**)mz[
/* ={k_ (8]
**Utility.java ]*&`J4i
*/ G)8H9EV
package NetFox; ;4s7\9o
ny'wS
N2Qb+
public class Utility { $ vt6~nfI
h2_A'
p`=v$_]?(
public Utility() cGUsao
{ i%3q*:A]2
LUfo@R
6-t:eo9
} 9H%dK^C
OBEHUJ5
//线程睡眠 o @(.4+2m
public static void sleep(int nSecond) 9lR-
{ m+=L}[
try{ =>Q$S
Thread.sleep(nSecond); h{/lW#[
} ur| vh5
catch(Exception e) 2SRmh!hr
{ l\"wdS}
e.printStackTrace (); Xwz'h;Ks_
} /1z3Q_M
} r=cm(AHF
9?Q0O\&uP
//日志 E(miQ
public static void log(String sMsg) #8CeTR23cw
{ d]I3zSIC
System.err.println(sMsg); i~i ?M)
} _(J4
n?S~(4%
&j!q9F
public static void log(int sMsg) Gg# 1k TK
{ J_}Rsp ED
System.err.println(sMsg); iVZX
} o!Y61S(
} xWxgv;Ah
Rl[SqmnI)@
mBON>Z[4.
/* J}Ji /
**TestMethod.java Rd|M)
*/ G"|c_qX
package NetFox; -40s
9FcH\2J
9w}_CCj3
public class TestMethod { X(qs]:
]\6*2E{1m
/:+MUw7~
public TestMethod() v%4zP%4Ak[
{ ///xx/weblogic60b2_win.exe [n2)6B\/
try{ 4Pkl()\c
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z11I1)%s
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :)j& t>aP
SiteFileFetch fileFetch = new SiteFileFetch(bean); +BgUnu26
fileFetch.start(); LjY@b
} xW+XN`77
catch(Exception e){e.printStackTrace ();} }S=m: VKH
@ev8"JZ1
AVi,+n
} Xp?WoC N
m*rw?nLZ
@M=\u-jJ.
public static void main(String[] args) wak`Jte=}m
{ q?=_{oH9
new TestMethod(); Ox^VU2K;&.
} _qU;`Q
} ~ea&1+Z[3
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