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)); 8=WX`*-uH
} (dQsR sA
for(int i=0;i<nEndPos.length-1;i++) ]<:qMLg
{ _g%h:G&^
nEndPos = nStartPos[i+1]; hZUnNQ
} 6a4-VX5
nEndPos[nEndPos.length-1] = nFileLength; @0fiui_
} _)-y&
} 3?uah'D5
O%m>4OdH
3\H0Nkubts
//启动子线程 OHK]=DH:M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ry"N_Fb
for(int i=0;i<nStartPos.length;i++) 905Lk>rB
{ >m4HCs>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l]F)]>AE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), YTV|]xpR
nStartPos,nEndPos,i); %%^by
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); llRQxk
fileSplitterFetch.start(); \!s0H_RJY
} hg+0!DVx
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OJXK]dZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ySNXjH Q=
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", cp L'
nEndPos = " + nFileLength); ]Aa.=
// fileSplitterFetch[nPos.length-1].start(); 'I5~<"E
baz~luM
/tu\q
//等待子线程结束 {]3Rk
//int count = 0; ~s-"u *>
//是否结束while循环 IpKpj"eoLy
boolean breakWhile = false; JXk<t5@D
lvk r2Meu<
fe+2U|y
while(!bStop) 7R=A]@
{ ?f4jqF~Fh
write_nPos(); G\/7V L
Utility.sleep(500); MRa |<yK
breakWhile = true; *Fm#Qek
T )"Uq
eWU@@$9
for(int i=0;i<nStartPos.length;i++) 7cly{U"
{ _aK4[*jnqh
if(!fileSplitterFetch.bDownOver) V J]S"
{ SEsLJ?Dv0
breakWhile = false; _>(qQ-Px
break; |5#iPw_wMY
} #uCE0}N@
} Rd>PE=u
if(breakWhile) V^qkHm e
break; a:}&v^v
OuV f<@a
5<mGG;F
//count++; sX|bp)Nw
//if(count>4) 8mv}-;
// siteStop(); *."a>?D~
} TY*uK
@Xl/<S&
kC=h[<'
System.err.println("文件下载结束！"); be+tAp`
} D5jZ;z}
catch(Exception e){e.printStackTrace ();} o 12wp
} aT20FEZ;
z P=3B%$
zjUT:#(k
//获得文件长度 %fB!XCW
public long getFileSize() 9P\R?~3
{ K4j2xSGeo
int nFileLength = -1; q.Vcb!*$
try{ ]}s'`44J9e
URL url = new URL(siteInfoBean.getSSiteURL()); -/gAb<=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6*%E4#4
httpConnection.setRequestProperty("User-Agent","NetFox"); vz}_^8O
P"ATqQG%D
l_0/g^(
int responseCode=httpConnection.getResponseCode(); _p,1m[&M
if(responseCode>=400) Oj0,Urs7
{ m1,yf*U
processErrorCode(responseCode); T;Zv^:]0
return -2; //-2 represent access is error )&wJ_(z
} *?s"~XVs
0)nY- f0
xI,7ld~
String sHeader; #S*cFnd
KdU&q+C^
@zAav>
for(int i=1;;i++) K %Qj<{)
{ Nd;,Wz]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _~a5;[~
//Utility.log(in.readLine()); /d prs(*K
sHeader=httpConnection.getHeaderFieldKey(i); v5g]_v*F
if(sHeader!=null) #SIIhpjA(
{ i5G"@4(
if(sHeader.equals("Content-Length")) lMRy6fzI
{ #F25,:hY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); y)#=8oci
break; aW@J]slg
} C .{`-RO
} $R_RKyXzo
else VMgO1-F
break; aOK,Mm:iO
} 04P!l
} 3Q_L6Wj~
catch(IOException e){e.printStackTrace ();} '?j,oRz^T
catch(Exception e){e.printStackTrace ();} ,G%?}TfC)
g*[DyIm
=b[q<p\
Utility.log(nFileLength); 9#D?wR#J=
oH]"F
a+#Aitd
return nFileLength; yjB.-o('
} {Tl|>\[P
f<}>*xH/k
!K5D:x
//保存下载信息（文件指针位置） CZ.XEMN\
private void write_nPos() YpwMfl4
{ aFtL_# U
try{ mCQn '{)
output = new DataOutputStream(new FileOutputStream(tmpFile)); <[w>Mbqj_
output.writeInt(nStartPos.length); ("5Eed
for(int i=0;i<nStartPos.length;i++) 9&7$oI$!J
{ hB 36o9|9
// output.writeLong(nPos); OF/DI)j3
output.writeLong(fileSplitterFetch.nStartPos); 2/M:KR
output.writeLong(fileSplitterFetch.nEndPos); ~ $QNp#dq
} FNB4YZ6
output.close(); VT~jgsY
} ``9`Xq
catch(IOException e){e.printStackTrace ();} =BNS3W6
catch(Exception e){e.printStackTrace ();} [7*$Sd
} <Z58"dg.5
+tSfx
1 wB2:o<
//读取保存的下载信息（文件指针位置） dlB?/J<
private void read_nPos() (cLcY%$
{ kjOPsz*0
try{ p5PTuJ>q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pJ;4rrSK
int nCount = input.readInt(); DC6xet{
nStartPos = new long[nCount]; >p,FAz>
nEndPos = new long[nCount]; \qB:z7I2
for(int i=0;i<nStartPos.length;i++) IolKe:'>@
{ >UDb:N[
nStartPos = input.readLong(); Wi3St`$
nEndPos = input.readLong(); +(qs{07A$
} +PGtO9}B
input.close(); 3I%F,-r
} ,s.{R
catch(IOException e){e.printStackTrace ();} Weu%&u-
catch(Exception e){e.printStackTrace ();} %}x$YDO
} =V(|3?N
Wp0L!X=0
|ZBHXv
private void processErrorCode(int nErrorCode) Rd^X.
{ _8eN^oc%
System.err.println("Error Code : " + nErrorCode); ZclZD{%8J
} 6y d/3k
XEvDtDR
0CFON2I
//停止文件下载 syR +;
public void siteStop() :L'U>)k
{ Y,;$RV@g
bStop = true; q]r?s%x
for(int i=0;i<nStartPos.length;i++) byB ESyV!O
fileSplitterFetch.splitterStop(); ZuIw4u(9
g9K7_T #W
01;
} iD-,C`
} q{*4BL'
//负责部分文件的抓取 6}xFE]Df-Y
**FileSplitterFetch.java ^geC?m
*/ %\ef Mhn
package NetFox; ghu8Eg,Y
yB~`A>~M
N5Rda2m
import java.io.*; E`aAPk_y
import java.net.*; U6M3,"?
~+r"%KnG
zJ7=r#b
public class FileSplitterFetch extends Thread { k,UezuV
dX8N7{"[
]pi8%.d
String sURL; //File URL r|W2I,P
long nStartPos; //File Snippet Start Position 1deNrmp%
long nEndPos; //File Snippet End Position ?}D|]i34
int nThreadID; //Thread's ID 1y)|m63&
boolean bDownOver = false; //Downing is over >nA6w$
boolean bStop = false; //Stop identical VM[U&g<8n
FileAccessI fileAccessI = null; //File Access interface Dd:;8Xo
SC6cFyp2
.o?"=Epo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \gE6KE<?p
{ u(92y]3,
this.sURL = sURL; :6}y gL*i
this.nStartPos = nStart; AtU!8Z
this.nEndPos = nEnd; L@t}UC
nThreadID = id; q;{# ~<"+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Kf!8PR$
} ~=xS\@UY =
?!$uMKyt
1tMs\e-
public void run() ,&X7D]
{ $Z8=QlG>
while(nStartPos < nEndPos && !bStop) k@i+gV%
{ gfW8s+
{Hp*BE
h;(#^+LH
try{ &!E+l<.RF
URL url = new URL(sURL); E)h&<{%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?'L3B4
httpConnection.setRequestProperty("User-Agent","NetFox"); zld[uhc>
String sProperty = "bytes="+nStartPos+"-"; TDtS^(2A7K
httpConnection.setRequestProperty("RANGE",sProperty); G6?+Qzr
Utility.log(sProperty); =eNh))]
a?]"|tQ'
>PD*)Uq&
InputStream input = httpConnection.getInputStream(); yS)73s/MrY
//logResponseHead(httpConnection); OB{d^e}
B]xZ 4Y
Gj%cU@2
byte[] b = new byte[1024]; 2V*<HlqOif
int nRead; SK@%r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C~&~Ano,
{ wgeR%#DW
nStartPos += fileAccessI.write(b,0,nRead); L9Gxqw
//if(nThreadID == 1) OE=]/([
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); snW=9b)m
} tAM t7p-
~H)s>6>#v
ygA~d9"
Utility.log("Thread " + nThreadID + " is over!"); WHM|kt
bDownOver = true; uN)o|7
//nPos = fileAccessI.write (b,0,nRead); 6zGM[2
} K Qz.g3,
catch(Exception e){e.printStackTrace ();} -/O_wqm#
} 86BY032H
} 2zz7/]?Q
e[(XR_EY
mEUdJvSG(
//打印回应的头信息 rrSsQq
public void logResponseHead(HttpURLConnection con) (<"uV%1
{ S3G9/
for(int i=1;;i++) \9%SR~
{ &H`AS6
String header=con.getHeaderFieldKey(i); %FDv6peH
if(header!=null) :E>"z6H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); HL^+:`,
Utility.log(header+" : "+con.getHeaderField(header)); s?irT;=
else ky^p\dMh
break; =@%Ukrd@
} #Oeb3U
} k[`9RGT
W8$ky[2R
v%=@_`Ht
public void splitterStop() 0^L>J"o
{ 007(k"=oV
bStop = true; 5a PPq~%
} ~T{^7"q\
~'[0-_]=f
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} [f?fA[,[
X(`wj~45VX
);]9M~$
/* |\lsTY&2
**FileAccess.java fnwhkL#8
*//文件访问(定位，写) vIL'&~C\y
package NetFox; L>&o_bzp
import java.io.*; Qrnc;H9)
!Rq.L
<:,m
public class FileAccessI implements Serializable{ /s'7[bSv
)H'SU_YU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %]2hxTV
RandomAccessFile oSavedFile; t8}R?%u
long nPos; r\+0J`
&7i o/d\/
s?:&#
public FileAccessI() throws IOException c,K)*HB
{ Zt;dPYq>
this("",0); PLkwtDi+&
} cL]vJ`?Ih
w=ib@_:f
8,0WHivg
public FileAccessI(String sName,long nPos) throws IOException Ly7|:IbC
{ Hz*5ZIw
oSavedFile = new RandomAccessFile(sName,"rw"); .9cQq/{b
this.nPos = nPos; x?aNK$A~X
oSavedFile.seek(nPos); ~6)A/]6
} Mx3MNX/
7O=N78M
bp>-{Nv
public synchronized int write(byte[] b,int nStart,int nLen) ;yvx-
{ !R;NV|.eI6
int n = -1; O7M8!3Eqm
try{ ``zgw\f[%
oSavedFile.write(b,nStart,nLen); #GJ{@C3H8Q
n = nLen; z^ai *
} eWgqds&#
catch(IOException e) GQ@`qYLZ+
{ b-d{)-G{(
e.printStackTrace (); =02$Dwr
} OzVCqq"]
H'Oy._,]t
)}/ ycTs
return n; + Z7 L&BI
} ,[} XK9
,R-T( <r
7z_EX8^
} JJHfg)
_uYidtxo=
\4/zvlo]h
/* OH(w3:;[8
**SiteInfoBean.java prWK U
*/ hLv~N}
package NetFox; lBpy0lo#
'^npZa'%sW
U9*uXD1\
public class SiteInfoBean { .~nk'm
y:m ;_U,%c
z(8:7 G
private String sSiteURL; //Site's URL vuNt+
private String sFilePath; //Saved File's Path !R 2;]d*
private String sFileName; //Saved File's Name KWq&<X5
private int nSplitter; //Count of Splited Downloading File @PaOQ@
T4M"s;::1
,w9:)B7
public SiteInfoBean() 'P:u/Sq?m
{//nSplitter的缺省值为5 i7%v2_
//default value of nSplitter is 5 B2R^oL'}
this("","","",5); uIvAmc4
} 1(q&(p
!LunoC>B
+E7Os|m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nT;Rwz$3
{ **D3.-0u&
sSiteURL= sURL; NMM$ m!zg
sFilePath = sPath; UdiogXZ
sFileName = sName; ,:E*Mw:
this.nSplitter = nSpiltter; __3s3YG
NrVE[Z#
)'+ tb\g
} G2 E4
9W7 ljUg
BidTrO
public String getSSiteURL() y^*o%2/
{ t1Zcr#b>
return sSiteURL; ~YH'&L.O
} v!>(1ROQ.=
=hP7Hea(N
|h7 d#V>
public void setSSiteURL(String value) 0E<xzYo
{ MzRliH8e
sSiteURL = value; `hVi!Q]*P
} @{X<|,W9w
J[k,S(Y
S{0iPdUC
public String getSFilePath() PX} ~
{ nB &[R
return sFilePath; z>6hK:27
} 4GN
#hQ#_7
NKSK+ll2
public void setSFilePath(String value) ;UAi>//#
{ gfW_S&&q
sFilePath = value; UGb<&)
} YcmLc)a7
GBvgVX<
F?Fs x)2k
public String getSFileName() N|N#-
{ s2X<b `
return sFileName; S#:yl>2
} TpSv7kT]
-r'/PbV0
2}BQ=%E!'
public void setSFileName(String value) rP7[{'%r
{ 4pJ #fkc^
sFileName = value; Bn<1zg5
} "8-;Dq'+
9K6G%
@~+W
public int getNSplitter() QyEGK
{ |c)hyw?[Y
return nSplitter; :,@\q0j"=
} 7;i [
dc+U#]tS
WSKubn?7B
public void setNSplitter(int nCount) @CUYl*.PD
{ e|e"lP
nSplitter = nCount; kR !O-@GJ]
} 6/=0RTd
} LK}*k/eG
;S5J"1)O~
MV?#g-5
/* SqosJ}K
**Utility.java %S$+3q%F
*/ ~ubcD6f
package NetFox; DmA~Vj!a^y
N+9W2n
?s-Z3{k
public class Utility { 5{Oq* |
S%p.|!
Ds<~JfVl
public Utility() +I>V9%%vW_
{ $[xS>iuD
itn<c2UyA
QUO'{;,
} Yf?hl
51Q m2,P1^
//线程睡眠 Q|7$SS6$
public static void sleep(int nSecond) Zn{Y+ce7d
{ {u(( y D
try{ TCLXO0
Thread.sleep(nSecond); Pea2ENe3
} @km@\w
catch(Exception e) 1va~.;/rG
{ :AYhBhitC
e.printStackTrace (); Rh :|ij>B
} "2=v:\~=
} #7r13$>!
B~h3naSe
//日志 _g2"D[I%
public static void log(String sMsg) *mjPNp'3{m
{ N!~5S`
System.err.println(sMsg); W'Y?X]xr
} 6BdK)s
) -^(Su(!
@j`gxM_-O
public static void log(int sMsg) ?e#bq]
{ xiy=D5N.=
System.err.println(sMsg); &~KAZ}xu
} Z4s+8cTHn
} WXs?2S*
kQw%Wpuq[/
A:4?Jd>
/* QF4)@ r{2x
**TestMethod.java 9q]n&5
*/ k4-S:kVo
package NetFox; ;W?mQUo:P8
(&!RX.i
Ial"nV0>0
public class TestMethod { wM1&_%N
\&MJ(F>vJ
{%+UQ!]d8
public TestMethod() .2{*>Dzi
{ ///xx/weblogic60b2_win.exe +:kMYL3
try{ Jq*Q;}n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ufn%sA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N#p%^GH
SiteFileFetch fileFetch = new SiteFileFetch(bean); dJF3]h Y
fileFetch.start(); H{4_,2h=m
} :SD#>eD0
catch(Exception e){e.printStackTrace ();} =eyPo(B
mfx-Ja_a
0t(2^*I?>
} I|<`Er-;58
p|>m 2(|
;Sl%I+?
public static void main(String[] args) KsSIX
{ -nQ(.#-n
new TestMethod(); x8o/m$[,=u
} ?3y>K!D(A
} ]NyN@9u@(
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