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)); 4D'AAr57
} )6!ji]c N
for(int i=0;i<nEndPos.length-1;i++) 5%r:hO @S
{ 7.mYzl-F(
nEndPos = nStartPos[i+1]; 9Sey&x
} If>bE!_BO
nEndPos[nEndPos.length-1] = nFileLength; )44c[Z
} @PL.7FM<v
} M)qb6aD0
W(#u^,$e[
c1Rn1M,2k
//启动子线程 f(Su
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; e 48N[p
for(int i=0;i<nStartPos.length;i++) R:+cumHr
{ Be$v%4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rv?4S`Z,x$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3< 'bi}{
nStartPos,nEndPos,i); 1m~-q4D)V
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W9D~:>^YP
fileSplitterFetch.start(); <5 )F9.$
} $-i(xnU/nl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), drwD3jx0xv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6*&$ha}X
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F tS"vJ\
nEndPos = " + nFileLength); 73p7]Uo
// fileSplitterFetch[nPos.length-1].start(); ''Y'ZsQ;
`R!%k]$
L*#W?WMM v
//等待子线程结束 *)Us
//int count = 0; |Cm6RH$(
//是否结束while循环 o#K*-jOfiH
boolean breakWhile = false; \[9^,QP
# 4&t09
14pyHMOR
while(!bStop) vojXo|c
{ J?9n4 u
write_nPos(); (Q?@LzCjy
Utility.sleep(500); y*#YIS56I
breakWhile = true; 71+ bn
|!q,J
elGwS\sw
for(int i=0;i<nStartPos.length;i++) mHyT1e
{ >bFrJz}
if(!fileSplitterFetch.bDownOver) kXroFLrY
{ L$z(&%Nx
breakWhile = false; A\w"!tNM|
break; h!mx/Hx
} ]3Y J a
} 5W!#,jz
if(breakWhile) &[z<p
break; WYN0,rv1:+
iLt2L;v>h
j Gp&P
//count++; 3GL,=q
//if(count>4) 3y%,f|ju
// siteStop(); LC,6hpmh
} Bra}HjHO
tbXl5x0
_)S['[
System.err.println("文件下载结束！"); ()Q#@?c~
} %"Ia]0
catch(Exception e){e.printStackTrace ();} (M2hK[
} X`20=x
>{)\GK0i7
-V&nlP
//获得文件长度 ~l8w]R3A
public long getFileSize() JT! Cb$!
{ ~p`[z~|
int nFileLength = -1; |ju+{+
try{ <Uy $b4h
URL url = new URL(siteInfoBean.getSSiteURL()); M%YxhuT0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); eiQ42x@Z
httpConnection.setRequestProperty("User-Agent","NetFox"); IP
,MjlA{0
c'INmc I|
int responseCode=httpConnection.getResponseCode(); m}(M{^\|
if(responseCode>=400) DkEf;P
{ 0|DyYu
processErrorCode(responseCode); fcTg/EXn
return -2; //-2 represent access is error &u!MI
} -asjBSo*D
skYHPwJdW
tM|/OJ7
String sHeader; t)5.m}
if?X^j0
e>m+@4*sn
for(int i=1;;i++) =h70!) Z5
{ DYF(O-hJK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QM'|k6
//Utility.log(in.readLine()); \fsNI T/
sHeader=httpConnection.getHeaderFieldKey(i); rvacCwI
if(sHeader!=null) P(UY}oU
{ ;\(LovUy6
if(sHeader.equals("Content-Length")) CofTTYl
{ 3a[LM!
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); dZY|6
break; rJ{k1H>
} Z,DSTP\|
} R=3|(R+kA
else +Ks3
break; "rrw~
} vm7ag 7@O
} q|}O-A*wa
catch(IOException e){e.printStackTrace ();} <TTBIXV
catch(Exception e){e.printStackTrace ();} A34O(fE
-,Js2+QZ#
~z(0XKq0d
Utility.log(nFileLength); nsM.`s@V
%d%FI"!K
P]iJ"d]+X
return nFileLength; !"ir}Y%
} H.;2o(vD
9^&B.6!6
-Q/wW4dE=
//保存下载信息（文件指针位置） wRZFBf~ :
private void write_nPos() 3 Q~0b+k
{ lcM
try{ 1gnLKfc
output = new DataOutputStream(new FileOutputStream(tmpFile)); }mo)OyIX
output.writeInt(nStartPos.length); dlA0&;}z
for(int i=0;i<nStartPos.length;i++) Xf{9rZ+
{ OnH3Ss$
// output.writeLong(nPos); )gD2wk(
output.writeLong(fileSplitterFetch.nStartPos); K_n GZ/`[
output.writeLong(fileSplitterFetch.nEndPos); 9I:3
} 3mHP=)
output.close(); lvRTy|%[
} j]U~ZAn,K
catch(IOException e){e.printStackTrace ();} wv`ar>qVL
catch(Exception e){e.printStackTrace ();} b%KcS&-6
} KG4zjQf
vw$b]MO!
nly}ly Q/
//读取保存的下载信息（文件指针位置） 9f/l"
private void read_nPos() Z&4L///
{ ;<*USS6X
try{ III:jhh
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ">M&/}4
int nCount = input.readInt(); 3ZN\F
nStartPos = new long[nCount]; ]9~Il#
nEndPos = new long[nCount]; P+y XC^ ,
for(int i=0;i<nStartPos.length;i++) g{ ;OgS3>
{ ,:#h;4!VRF
nStartPos = input.readLong(); a*t @k*d_
nEndPos = input.readLong(); r7#.DJnN.
} W56VA>ia
input.close(); >l #D9%
} "[rz*[o8I
catch(IOException e){e.printStackTrace ();} &grvlK
catch(Exception e){e.printStackTrace ();} E,dUO;
} #?`S+YN!q)
_#Lq~02 %
]t~'wL#Z
private void processErrorCode(int nErrorCode) yeMe2Zx
{ `e`DSl D>
System.err.println("Error Code : " + nErrorCode); ,hrv
} "Ec9.#U/
NcHU)
ao0^;
//停止文件下载 orYZ<,u
public void siteStop() U<r!G;^`
{ S&.xgBR
bStop = true; mfF `K2R
for(int i=0;i<nStartPos.length;i++) XH(-anU"!P
fileSplitterFetch.splitterStop(); w ~"%&SNN
TyA1Qk\
BR-wL3x b
} .S1MxZhbP
} ji\&?%(B
//负责部分文件的抓取 MIyT9",Pl
**FileSplitterFetch.java ,6#%+u}f
*/ WJ)4rQ$o
package NetFox; .LDp.#d9r1
LitdO>%#2
k ]T
import java.io.*; .XkD2~;
import java.net.*; a\~118 !
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!Eb|AHa
public class FileSplitterFetch extends Thread { ? HNuffk
$iMLT8U
Qg]A^{.1
String sURL; //File URL !G6h~`[
long nStartPos; //File Snippet Start Position ,j9?9Z7R
long nEndPos; //File Snippet End Position ._t1eb`m{
int nThreadID; //Thread's ID {-MjsBR
boolean bDownOver = false; //Downing is over fFoZ!H
boolean bStop = false; //Stop identical 19-V;F@;
FileAccessI fileAccessI = null; //File Access interface m>F:dI
-/0aGqY
n(|n=P:o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j:>0XP
{ 4.uaWM)2
this.sURL = sURL; e2K9CE.O
this.nStartPos = nStart; &cd>.&1<2
this.nEndPos = nEnd; p@Cas
nThreadID = id; T$AVMVq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A0RSNAM
} 'x<oILOG
2`%a[t@M.
hSXJDT2
public void run() K3UN#G)U
{ |:Maa6(W
while(nStartPos < nEndPos && !bStop) 0*9xau{(
{ ho B[L}<c
[k(b<'
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try{ @|sBnerE
URL url = new URL(sURL); m2YsE j7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U* c'xoP
httpConnection.setRequestProperty("User-Agent","NetFox"); -'L~Y~'.
String sProperty = "bytes="+nStartPos+"-"; ,Vo[mB
httpConnection.setRequestProperty("RANGE",sProperty); H3`.Y$z
Utility.log(sProperty); @$ju Qm
].5q,A]
~t/i0pKq.
InputStream input = httpConnection.getInputStream(); M#-E
//logResponseHead(httpConnection); l(-"rE
`@WJ_-$#
g]c6_DMfb1
byte[] b = new byte[1024]; $o;c:Kh$$
int nRead; hQ!59
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j_~mP>el)
{ L, #|W
nStartPos += fileAccessI.write(b,0,nRead); '*&dP"
//if(nThreadID == 1) ^c>Bh[
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;"ESN)*|i
} ]NI CQ9
!4FOX>|L@
nT+ZSr
Utility.log("Thread " + nThreadID + " is over!"); u<N`;s
bDownOver = true; q,%Fvcmx+e
//nPos = fileAccessI.write (b,0,nRead); /3tErc'
} olA+B
catch(Exception e){e.printStackTrace ();} C^;8M'8z0
} r\FZ-gk}Q
} = &?&}pVF
rly%+B `/
HRjbGc|[
//打印回应的头信息 3&5b!Y
public void logResponseHead(HttpURLConnection con) o)n)Z~
{ D/ sYH0.V$
for(int i=1;;i++) l?rLadvc
{ CY{!BV'
String header=con.getHeaderFieldKey(i); INp:;
if(header!=null) `4X.UPJ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5*-RIs! 2
Utility.log(header+" : "+con.getHeaderField(header)); /988K-5k
else '6e4rn{
break; )G?\{n-
} pwS"BTZ
} f-|zh#L
j;V\~[I^u
sLJ]N0t
public void splitterStop() /V`SJ"
{ L6i|5 P
bStop = true; k~K;r8D/
} S:`Gi>D
0sH~yvM5
|HYST`
} %6rSLBw3
V9qA'k
GG<0k\RN
/* U{bv|vF
**FileAccess.java IbL'Z
*//文件访问(定位，写) N-&ZaK
package NetFox; ]jn1T^D'
import java.io.*; <6Y;VH^_
TU2oQ1
s^IC]sW\%
public class FileAccessI implements Serializable{ r\F2X J^
$F9w0kz:,*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i=]R1yP
RandomAccessFile oSavedFile; L-rV+?i`6f
long nPos; DO~[VK%|
)?{!7/H F@
WQze|b%
public FileAccessI() throws IOException Y<(7u`F
{ }7b{ZbDI
this("",0); eyp_.1C~
} IDD`N{EA
TQNdBq5I6
89GW!
public FileAccessI(String sName,long nPos) throws IOException XTk :lzFH
{ |2n*Ds'
oSavedFile = new RandomAccessFile(sName,"rw"); im9EV|;
this.nPos = nPos; pU<J?cU8N
oSavedFile.seek(nPos); bc~$"
} 9&Un|cr
T+zhj++
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public synchronized int write(byte[] b,int nStart,int nLen) 8-7Ml3G*
{ EW vhT]<0
int n = -1; +HRtuRv0T
try{ =q)+_@24>d
oSavedFile.write(b,nStart,nLen); UR=s=G|
n = nLen; ?wv3HN
} Vn:v{-i
catch(IOException e) \9tJ/~
{ =T26vu
e.printStackTrace (); tjB)-=j[
} );iJ9+ V}
;-Os~81o?
]3,
return n; DO-M0L
} ?E V^H-rr
@lWNSf
$IX(a4'
} ub9[!}r't
4q7H
4|I;z
/* Ja4M@z
**SiteInfoBean.java %saP>]o
*/ }qoId3iY!7
package NetFox; r(Z?Fs/
Gf9sexn]l
&Ejhw3Nw
public class SiteInfoBean { Bhx.q,X
mLkp*?sfC
'jE/Tre^
private String sSiteURL; //Site's URL (jhi<eV
private String sFilePath; //Saved File's Path KWD{_h{R
private String sFileName; //Saved File's Name y(22m+B
private int nSplitter; //Count of Splited Downloading File X"`[&l1
_z%~m2SP
bXc*d9]
public SiteInfoBean() lX2:8$?X
{//nSplitter的缺省值为5 0<uLQVoR2n
//default value of nSplitter is 5 pM+9K:^B
this("","","",5); =-/'$7R,
} {dxl8~/I
H Q[
$M0l (htR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) y4|<+9<7
{ I~YV&12
sSiteURL= sURL; `uk=2k}&m
sFilePath = sPath; j7a}<\
sFileName = sName; _unoDoB
this.nSplitter = nSpiltter; cpw=2vnD
;Gn>W+Ae M
4I2:"CK06
} %g5#q64
J!6w9,T_
>b9J!'G,(
public String getSSiteURL() *q,nALs
{ Ja5od
return sSiteURL; g@s`PBF7`
} ,YBO}l
)p;t '*]
8EdaqF
public void setSSiteURL(String value) [bX^_ Y
{ dyf>T}Iy
sSiteURL = value; V6_":L"!
} >?ar
NT5##XOB
hWFOed4C
public String getSFilePath() >Z3>
{ -Q5UT=^
return sFilePath; 4 $Kzh
} ._A4:
&J|I&p
2-ksr}:
public void setSFilePath(String value) =L1%gQJJ&
{ )!E:
sFilePath = value; L;vglS=l;
} cmU0=js.
=?+w5oI0
T95FoA
public String getSFileName() _7';1 D
{ lqh:c
return sFileName; B=^M& {
} n{~&^Nby*I
g@M5_I(W
<3N\OV2
public void setSFileName(String value) j x< <h_j
{ rwW"B
sFileName = value; %`$:/3P$U
} >d"\
i?@7>Ca
Evg#sPu\
public int getNSplitter() KVEc:<|x
{ _99 +Vjy
return nSplitter; h:C:opa-=
} |x&4vHXR0
MNTVG&h
33eOM(`D[
public void setNSplitter(int nCount) *sB'D+-/
{ +lFBH(o]X
nSplitter = nCount; cp~6\F;c
} HA}q.L]#
} ?z-nY,'^uq
W=+AU!%
XUR#|
/* i,Z-UA|f=T
**Utility.java .=G3wox3
*/ s[UV(::E
package NetFox; hR2 R
cw)J+Lyh
FqnD"]A
public class Utility { + `'wY?
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B%tj-h(a
public Utility() R8!~>$#C6)
{ U61 LMH
Zm++5b`W/[
[h' 22W
} b">"NvlB
AA ~7"2e
//线程睡眠 47*2QL^zj
public static void sleep(int nSecond) E#tfCM6
{ vZS/?pU~~
try{ ;"EDFH#W
Thread.sleep(nSecond); SJLs3iz_)
} "W4|}plnu
catch(Exception e) Yh"9,Z&wiR
{ ngd4PN>{4
e.printStackTrace (); i Pl/I
} zp'hA
} ?;5/"/i
Nknd8>Hy+
//日志 -H[@]Q4w
public static void log(String sMsg) !{(crfXB
{ jY/(kA]}
System.err.println(sMsg); +:70vZc:V@
} A>S7Ap4z>
7oUo[
Rw[!Jq
public static void log(int sMsg) 8(q8}s$>
{ 48J{Y3F
System.err.println(sMsg); Zg4wd/y?
} 3|G~_'`RLt
} 9<P%?Q
J?Q@f
@{3_7
/* GvA4.s,
**TestMethod.java +@8, uL
*/ I3x+pa^]2
package NetFox; /L! =##
"iK'O =M
0lYP!\J3]%
public class TestMethod { PV=sqLM~
&n83>Q
RCK*?\m5
public TestMethod() Y}yh6r;i
{ ///xx/weblogic60b2_win.exe 3w[uc~f
try{ |@R/JGB^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &lzCRRnvt
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tN.BI1nB
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,5t_}d|3C=
fileFetch.start(); @ZV>Cl@%2
} -\ew,y
catch(Exception e){e.printStackTrace ();} I7'v;*
KlBT9"6"
=R9`to|
} _XrlCLp: d
{Q]7!/>>
Z.aeE*Hs$
public static void main(String[] args) juM~X5b
{ P^lRJB<$Q
new TestMethod(); mc,HliiJ
} ,L>{(Q)
} 9v ,y
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