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)); t o2y#4'.
} VH2/
for(int i=0;i<nEndPos.length-1;i++) 2E_*'RT
{ \bzT=^Z;2
nEndPos = nStartPos[i+1]; !:|[?M.`
} [>wvVv
nEndPos[nEndPos.length-1] = nFileLength; =V*4&OU
} @(_f}SgfE
} HC\\w-`<
y&{ Z"+B5
a-Ef$(i_
//启动子线程 :MbD=sX
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %x zgTZ
for(int i=0;i<nStartPos.length;i++) 7<p?E7
{ IQA<xqX
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oxq} dX7S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?)V}_%fVv
nStartPos,nEndPos,i); _rjLCvv-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xzjG|"a[GB
fileSplitterFetch.start(); |y~un9j+
} q26%Z)'nf
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .?CumaU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); AiE\PMF~{P
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y.m;4((
nEndPos = " + nFileLength); At=l>
// fileSplitterFetch[nPos.length-1].start(); dgsD~.((A
'I *&P5|
Vj{}cL"MR
//等待子线程结束 k9iXVYQ.;r
//int count = 0; Yt% E,U~g
//是否结束while循环 [J6b5
boolean breakWhile = false; b/g"ws_
T24?1
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while(!bStop) Vn1hr;i]
{ %/(>>*}Kw|
write_nPos(); 6 SosVE>Z
Utility.sleep(500); =-GHs$u%f
breakWhile = true; Ap[}[:U
M$Of.
l-mf~{
for(int i=0;i<nStartPos.length;i++) '5n67Hl 1
{ o)hQ]d
if(!fileSplitterFetch.bDownOver) 4;hgi[
{ :x<'>)6
breakWhile = false; {Z=m5Dy}
break; wWNHZv&
} ugI9rxT]Kv
} /kY|PY
if(breakWhile) P,[O32i#
break; CL-mt5Kx#7
s s*% 3<
@Ja8~5:
//count++; CNiUHUD
//if(count>4) !7O!)WJ
// siteStop(); ]O\Oj6C
} NHCdf*
m% {4
ZAG iaq
System.err.println("文件下载结束！"); a|x1aN0
} .#] V5g,
catch(Exception e){e.printStackTrace ();} R]7-6
} E\(dyq/
hF!t{ Lf3
>7VOytc
//获得文件长度 =nYd|Ok
public long getFileSize() O,kzU,zOs
{ /@<Pn&Rq
int nFileLength = -1; z3 lZ3
try{ L]goHs
URL url = new URL(siteInfoBean.getSSiteURL()); Qw ukhD7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &O'6va
httpConnection.setRequestProperty("User-Agent","NetFox"); gqje]Zc<
lKMOsr@l
;:a>#{N
int responseCode=httpConnection.getResponseCode(); @k!J}O K
if(responseCode>=400) oT4A|M
{ fq.ui3lP)
processErrorCode(responseCode); ]i-peBxw
return -2; //-2 represent access is error `;ofQz4
} p. eq N
Y?(kE` R
3f2%+2Zjt,
String sHeader; A?V[/
ERO'{nT&
swBgV,;
for(int i=1;;i++) k|$08EK$
{ >Q$, } `U;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4E`y*Hmzy+
//Utility.log(in.readLine()); 3Ms` ajJ
sHeader=httpConnection.getHeaderFieldKey(i); +ou ]|
if(sHeader!=null) xm}9(EJ
{ KVVo_9S'
if(sHeader.equals("Content-Length")) (3DjFT3 w
{ Lbka*@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I6x
break; HWJ(O/N
} 3iHUG^sLW
} hlpi-oW`
else iyF~:[8
break; mTcopyp
} SO#NWa<0|
} 2g elmQnc
catch(IOException e){e.printStackTrace ();} FC:Z9{2!
catch(Exception e){e.printStackTrace ();} |0A"3w
4LRrrW
vps</f!
Utility.log(nFileLength); v2e*mNK5
=l_B58wrx
)uvs%hK
return nFileLength; @_Ko<fKSX
} "lcNjyU\O
wo($7'.@
e`pYO]Z
//保存下载信息（文件指针位置） Ak`7f$z
private void write_nPos() wN"j:G(
{ G x;U 3iV
try{ !o+Y"* /
output = new DataOutputStream(new FileOutputStream(tmpFile)); g\CRx^s
output.writeInt(nStartPos.length); ~C1lbn b
for(int i=0;i<nStartPos.length;i++) i`3h\ku
{ `ZCeuOH
// output.writeLong(nPos); ^ lrq`1k
output.writeLong(fileSplitterFetch.nStartPos); (!72Eaw:]
output.writeLong(fileSplitterFetch.nEndPos); .E'Tfa
} CdCo+U5z{
output.close(); B{UL(6\B
} eI8rnp(Ia
catch(IOException e){e.printStackTrace ();} {sn RS)-
catch(Exception e){e.printStackTrace ();} &b[.bf
} xV&c)l>}
\K$9r=!(
sN`2"t/s
//读取保存的下载信息（文件指针位置） g.wp }fz
private void read_nPos() |JZ3aS
{ v~f_~v5J!
try{ #k%$A}9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &cDLSnR
int nCount = input.readInt(); Hc`)Q vFRW
nStartPos = new long[nCount]; EwvW: t1
nEndPos = new long[nCount]; 'R&Y pR
for(int i=0;i<nStartPos.length;i++) X]^FHYjhS
{ BI\ )vr$
nStartPos = input.readLong(); ]JQ7x[
nEndPos = input.readLong(); : +Na8\d
} DQC=f8
input.close(); G:$Ta6=
} F*`*5:7
catch(IOException e){e.printStackTrace ();} ?b?6/_W~R
catch(Exception e){e.printStackTrace ();} S$ u`)BG):
} Wpgp YcPS
HeV6=&#
@>>8CU^~
private void processErrorCode(int nErrorCode) KIY/nu
{ tPv3nh
System.err.println("Error Code : " + nErrorCode); dQX<X}
} 5*M3sN
>?-etl
x$:>W3?T=^
//停止文件下载 C`qo
public void siteStop() #&fi[|%X$
{ J7Z`wjX1
bStop = true; HPz9Er
for(int i=0;i<nStartPos.length;i++) 7R4sd
fileSplitterFetch.splitterStop(); :{:R5d(_I
%sd1`1In
N_3$B=
} mGss9eZa
} ]!@z3Hv3
//负责部分文件的抓取 rG#o*oA
**FileSplitterFetch.java $1aJdZC7
*/ 4RPc&%
package NetFox; o!nw/7|
YJBlF2uD
s|p,UK
import java.io.*; vpt*?eR
import java.net.*; Z7\}x"hk
x;Qs_"t];3
I},]Y~Y3
public class FileSplitterFetch extends Thread { R^v-%mG9
uu5AW=j
MR=dQc
String sURL; //File URL gLm ]*
long nStartPos; //File Snippet Start Position 9%{V?r]k
long nEndPos; //File Snippet End Position 6wIo95`
int nThreadID; //Thread's ID ]2:w?+T
boolean bDownOver = false; //Downing is over UweXz.x7
boolean bStop = false; //Stop identical QCm93YZs6E
FileAccessI fileAccessI = null; //File Access interface 54X=58Q
*$%ch=
ld*W\
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h/'b(9fS
{ CcGE4BB
this.sURL = sURL; sBN"eHg
this.nStartPos = nStart; QcW6o,
this.nEndPos = nEnd; , %8keGhl
nThreadID = id; LS"_-4I}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8iv0&91Z
} }PC_qQF
ID{62>R
}s9eRmJs
public void run() V-1H(wRu
{ 5|nT5oS
while(nStartPos < nEndPos && !bStop) 4q9+a7@
{ Yz%AKp
":qhO0
"3&bh>#qY
try{ UyFvj4SU
URL url = new URL(sURL); g2Hz[C(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A7`+XqG
httpConnection.setRequestProperty("User-Agent","NetFox"); 2F}D?]A
String sProperty = "bytes="+nStartPos+"-"; vkR,Sn
httpConnection.setRequestProperty("RANGE",sProperty); M0jC:*D`"
Utility.log(sProperty); =d+~l
)9pRT dT
oouhP1py,
InputStream input = httpConnection.getInputStream(); +69[06F
//logResponseHead(httpConnection); tv]^k]n{rf
`6No6.\J
;hf{B7
byte[] b = new byte[1024]; /JqNiqvh
int nRead; **,(>4j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0Z.X;1=
{ bjL8Wpk
nStartPos += fileAccessI.write(b,0,nRead); a)o-6
//if(nThreadID == 1) U%:K11Kr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u5'jIqlU
} ;bYpMcH
hL?"!
q PveG1+25
Utility.log("Thread " + nThreadID + " is over!"); Qhc>,v)
bDownOver = true; Ii.0Bul
//nPos = fileAccessI.write (b,0,nRead); ZwFVtR
} 'K!u}py
catch(Exception e){e.printStackTrace ();} lH%%iYBM
} F.Sc2n@7-
} .or1*-B K
RJ+["[k
za,JCI
//打印回应的头信息 dED&-e#
public void logResponseHead(HttpURLConnection con) <rKfL`8p
{ +|w%}/N
for(int i=1;;i++) m=4hi(g
{ LBIsj}e
String header=con.getHeaderFieldKey(i); ^~7/hm:
if(header!=null) af>^<q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5/E7@h ,
Utility.log(header+" : "+con.getHeaderField(header)); n40&4n
else n>XfXt =
break; U =i=E}'
} v =]!Po&Q-
} Hob n{E
"\~d!"n|2
qS!U1R?s
public void splitterStop() U/s!Tb>`
{ }2]m]D@%7
bStop = true; ,]LsX"u
} &y+)xe:&S
r.ib"W#4
2v\<MrL
} PKg>|]Rf.
=M],5<2;
>(\Z-I&YQ
/* lc(}[Z/|V
**FileAccess.java Gl6M(<f\5
*//文件访问(定位，写) VBN=xg}
package NetFox; <hBd #J
import java.io.*; }Y&|v q
PNB E
BCI[jfd7
public class FileAccessI implements Serializable{ |44 E:pA
C@P*:L_
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _@D"XL#L
RandomAccessFile oSavedFile; [Te"|K':
long nPos; \Gm\sy
.jv#<"DW
?3yrX_Qm{
public FileAccessI() throws IOException (hi{i
{ 2DXV~>
this("",0); Q35D7wo'}
} IIY3/
|@Ze{\
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public FileAccessI(String sName,long nPos) throws IOException N Wf IRL
{ RQ;}+S
oSavedFile = new RandomAccessFile(sName,"rw"); .L8g(F(=:
this.nPos = nPos; L#`Vr$
oSavedFile.seek(nPos); r!&}4lHYi
} s(8e)0Tl
'&!:5R59
c2Yrg@) [
public synchronized int write(byte[] b,int nStart,int nLen) $)Ty@@7C
{ yfZYGhPN(
int n = -1; $2>"2*,04
try{ _W
oSavedFile.write(b,nStart,nLen); oqa8v6yG'
n = nLen; 0]Qk*u<
} y1bo28
catch(IOException e) V|vXxWm/
{ 'j$n;3
e.printStackTrace (); V)Ze>Pp
} )W^$7Em
^D?{[LBc
62 9g_P)
return n; s-Qq#T
} kLe{3>}j
6^sH3=#
i'3)5
} b6d}<b9#
7qLB9r
M-/2{F[
/* #]*]qdQWV^
**SiteInfoBean.java NJmyp!8
*/ )S^[b2P]y_
package NetFox; * zc[t
3a0% J'
3XIL; 5
public class SiteInfoBean { Gg y7xb
5"&=BD~D
.\7AJB\l
private String sSiteURL; //Site's URL ~BC~^D&WD
private String sFilePath; //Saved File's Path 6T6UIq
private String sFileName; //Saved File's Name 8|~M!<
private int nSplitter; //Count of Splited Downloading File l9naqb:iP
M:t"is
yJ*g ;
public SiteInfoBean() m1DrT>oN'
{//nSplitter的缺省值为5 i?D)XXB85
//default value of nSplitter is 5 |w.h97fj
this("","","",5); D77s3AyHK
} "eIE5h
TGZr [
e3WEsD+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >">grDX
{ ss4YeZa
sSiteURL= sURL; E&;;2
sFilePath = sPath; KvumU>c#A
sFileName = sName; N=j$~,yG
this.nSplitter = nSpiltter; o('6,D
df{6!}/(
;v5Jps2^]
} Ga\kvMtr
v+W4wD
sMcN[r
public String getSSiteURL() U nS|""
{ tja7y"(]
return sSiteURL; bO+e?&vQ%
} LY2QKjgP
k1fX-2H
TTJj=KPA
public void setSSiteURL(String value) 3Qd%`k
{ cd;~60@K
sSiteURL = value; $9ys! <g
} fv:&?gc
h]WW?.
,p V3O`z
public String getSFilePath() I^m9(L4%
{ I\f\k>;
return sFilePath; p/gf
} &R3#? 1,
IZ@M K
sOm&7A?
public void setSFilePath(String value) {j%7/T{
{ /\U:F
sFilePath = value; Go !{T
} `!C5"i8+i2
PoZxT-U
FSb4RuD9
public String getSFileName() O)INM
{ UB]]oC<
return sFileName; vvP]tRZ
} Bkdt[qDn5P
-H$C3V3]
3aFD*S
public void setSFileName(String value) gp4@6HuUd
{ 5UvqE_
sFileName = value; Y{<SD-ibZ$
} 6*s:I&
CK8!7=>}^
@O8X )
public int getNSplitter() *z__$!LR
{ O5ZR{f&
return nSplitter; q{pa _
} Q+dLWFI
AdWP
Is>~P*2Y=
public void setNSplitter(int nCount) U,V+qnS
{ *rmM2{6
nSplitter = nCount; S'=}eeG
} 7w.9PNhy
} hlGrnL
.Ix[&+LsY
iu QMVtv
/* ORhvo,.u
**Utility.java d?A!0;(*
*/ J#?z/3v(
package NetFox; 8b< 'jft
!fG}<6&i
.QB)Y* z
public class Utility { 8UXtIuQ
< mp_[-c
[#;CBs5o
public Utility() S^nI=HTm
{ >~})O&t
Ly]J-BTe
WT:ZT$W
} :~'R|l
c.}#.-b8
//线程睡眠 z7R2viR[
public static void sleep(int nSecond) <P#:dS%r
{ [I=1
try{ F_~A8y
Thread.sleep(nSecond); Z |<
} sZ#U{LI
catch(Exception e) `W2 o~r*&
{ xo#K_"E
e.printStackTrace (); =$uSa7t#
} F87c?Vh)K
} 6!v$"u|[!'
vAfYONU
//日志 nTr{D&JS
public static void log(String sMsg) ;8yEhar
{ FMz>p1s|dK
System.err.println(sMsg); i)7B :uA
} 6@Ir|o
B4x@{rtER
Wx|De7*
public static void log(int sMsg) uVa`2]NV r
{ YFeL#)5y
System.err.println(sMsg); ))E| SAr
} WZcAwYB
} UHX,s
~;0W +
^a=V.
/* 7myYs7N8[
**TestMethod.java r+,JM L
*/ t_id/
package NetFox; d?N[bA
MC%!>,tC
*`V r P
public class TestMethod { K?*p|&Fi?8
g:Ry.=F7W
4f'!,Q ;
public TestMethod() YtA<4XHU
{ ///xx/weblogic60b2_win.exe #aIV\G
try{ t]8nRZ1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,ygDNF
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); TsY nsLQY
SiteFileFetch fileFetch = new SiteFileFetch(bean); |J:m{
fileFetch.start(); r)oR`\7
} BF /4
catch(Exception e){e.printStackTrace ();} rAA?{(!9x
X-`PF
+7r?vo1
} DtkOb,wY
synueg
qq>Qi(>
public static void main(String[] args) p']{WLDj2
{ .@@&q4=&
new TestMethod(); c=33O,_
} &<t`EI];)4
} |N:kf&]b
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