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)); (eOzntp8
} |?tUUT!`t
for(int i=0;i<nEndPos.length-1;i++) 2GHmA_7P
{ ks=l Nz9
nEndPos = nStartPos[i+1]; vuOixAkw
} I`~ofq?r
nEndPos[nEndPos.length-1] = nFileLength; rTgCmr'&
} + \DGS
} CfSpwkg
{5$.:Y
U1Z.#ETnM
//启动子线程 ?0{8fGM4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; cr&sI=i
for(int i=0;i<nStartPos.length;i++) SXA`o<Ma
{ AaVj^iy/X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $Ka-ZPy<#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 7AE)P[
nStartPos,nEndPos,i); "wB~*,Ny
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |fJpX5W-l
fileSplitterFetch.start(); w=]bj0<A=
} D]{#!w(d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?dJ[?<aG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6zJ<27
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", y" (-O%Pe
nEndPos = " + nFileLength); XJs*DK
// fileSplitterFetch[nPos.length-1].start(); 2itJD1;
)_|;h2I
tqnvC UIE
//等待子线程结束 sO5~!W>Z
//int count = 0; (sXR@Ce$
//是否结束while循环 VdVUYp
boolean breakWhile = false; 0E6tH& ;>
Jvk!a~e
nkv+O$LXP
while(!bStop) dK5|tWJX
{ Q :<&<i=I
write_nPos(); ^UB<U#8,
Utility.sleep(500); ':}
breakWhile = true; xXCSaBS~
:r{;'[38
?l6NQ;z
for(int i=0;i<nStartPos.length;i++) ^9{mjy0Q
{ ^F>C|FJ2
if(!fileSplitterFetch.bDownOver) yc#0c[ZQu
{ lji&]^1
breakWhile = false; ifA)Ppt<`
break; 8BL]]gT-I
} *gq~~(jH
} Z'vic#
if(breakWhile) *0K@^Db-
break; QO0#p1fom'
q&j4PR{
<vMdfw"(
//count++; 4\cJ}p}LZ{
//if(count>4) IQ${2Dpg[
// siteStop(); Znv3h
} xJQ-k/`
&2~c,] 9C
O?6ph4'
System.err.println("文件下载结束！"); 8"fZ>XQ
} b6@(UneVM
catch(Exception e){e.printStackTrace ();} Zj(2$9IU
} |;G9K`8
rF/k$_bFt
M<4tjVQ6
//获得文件长度 $jpAnZR- /
public long getFileSize() (}]ae*
{ :y>$N(.8f
int nFileLength = -1; z1-JoZ
try{ TqvgCk-
URL url = new URL(siteInfoBean.getSSiteURL()); f1hjU~nJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zNZ"PYh<u
httpConnection.setRequestProperty("User-Agent","NetFox"); j}uVT2ZE%
*J ]2"~_.
i]>)'i
int responseCode=httpConnection.getResponseCode(); ?)8OC(B8q
if(responseCode>=400) yX-h|Cr"
{ s+EJXoxw
processErrorCode(responseCode); -<Wv7FNpD
return -2; //-2 represent access is error Y-0o>:SM
} ]vFtByqn
&jg..R
=i`#0i2(
String sHeader; 'b?Px}
(M>[D!Yt
B 66-l!xa
for(int i=1;;i++) -f{NVX\<0
{ 'Ti7}K
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jjT|@\-u
//Utility.log(in.readLine()); %yVboA1
sHeader=httpConnection.getHeaderFieldKey(i); h#Z5vH
if(sHeader!=null) .L#xX1qr
{ @@?P\jv~
if(sHeader.equals("Content-Length")) bv%A;
{ %,Pwo{SH
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ySS kw7
break; uxxS."~
} e\9H'$1\
} UBgheu
else Vb _W&Nwd
break; L.%N
} \Q CH.~]
} A6D@#(D
catch(IOException e){e.printStackTrace ();} f vAF0 a
catch(Exception e){e.printStackTrace ();} -0 e&>H%
gbC!>LV
H{XD>q.
Utility.log(nFileLength); 6r|BiHP
=GP~h*5es
NoR=:Q 9e
return nFileLength; ~h:/9q
} @(~m.p|
eSC69mfD
p+t79F.js
//保存下载信息（文件指针位置） ggy 7p44
private void write_nPos() jkN-(v(T
{ b<1k$0J6
try{ nB8JdM2h{
output = new DataOutputStream(new FileOutputStream(tmpFile)); -F]0Py8(
output.writeInt(nStartPos.length); bG'"l qn
for(int i=0;i<nStartPos.length;i++) 5bfd8C
{ |t1ij'N
// output.writeLong(nPos); S7I8BS[*v
output.writeLong(fileSplitterFetch.nStartPos); :k-(%E](
output.writeLong(fileSplitterFetch.nEndPos); Sh]g]xR
} U1.w%b,
output.close(); K;n5[o&c
} >z,SN
catch(IOException e){e.printStackTrace ();} 6F@2:]W
catch(Exception e){e.printStackTrace ();} SEL7,8 Hm
} bnm3 cR:h"
lrE|>R
gvoo1 Sa
//读取保存的下载信息（文件指针位置） ;&A%"8o
private void read_nPos() e%B;8)7
{ ~&UfnO
try{ ZjOUk;H?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `;:zZ8*
int nCount = input.readInt(); jP{W|9@(
nStartPos = new long[nCount]; @S-p[u
nEndPos = new long[nCount]; _6"YWR
for(int i=0;i<nStartPos.length;i++) -f4>4@y
{ t$*V*gK{
nStartPos = input.readLong(); E&RiEhuv
nEndPos = input.readLong(); 0Xke26ga
} " iKX-VIl
input.close(); TqZ&X|G
} ,rO>5$w.
catch(IOException e){e.printStackTrace ();} $PNS`@B
catch(Exception e){e.printStackTrace ();} Xyf7sHQ
} RH"&B`
.;:jGe(
OE"r=is
private void processErrorCode(int nErrorCode) FTA[O.tiG
{ |.qK69
System.err.println("Error Code : " + nErrorCode); :.K#=ROP
} `4&a"`&$
>o#^)LN
~kkwPs2V
//停止文件下载 ~I_v {
public void siteStop() _i-(`5
{ DM73 Nn^5
bStop = true; %"1*,g{
for(int i=0;i<nStartPos.length;i++) MmvMuX]#)
fileSplitterFetch.splitterStop(); 9T#JlV
EE^ N01<"\
cSkJlhwNn
} }'FNGn.~#
} r2Wx31j{
//负责部分文件的抓取 pFUW7jE
**FileSplitterFetch.java mHnHB.OL
*/ )Q!3p={S*
package NetFox; */kX|Sur
.&Vyo<9Ck
Wb|xEwqd`
import java.io.*; U'Xw'?Uj
import java.net.*; "]"!"#aMv
!GNLq.rQ
"(U%Vg|)
public class FileSplitterFetch extends Thread { !aVwmd'9
]Q%|69H}B
syseYt]
String sURL; //File URL Yy_o*Ozq
long nStartPos; //File Snippet Start Position nCj_4,O
long nEndPos; //File Snippet End Position 9aE.jpN
int nThreadID; //Thread's ID T\Zq/Z\
boolean bDownOver = false; //Downing is over ?;//%c8,.
boolean bStop = false; //Stop identical TDMyZ!d
FileAccessI fileAccessI = null; //File Access interface !.[N(%"
/j{`hi
0UHX Li47Y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Gm]]Z_
{ @`</Z)
this.sURL = sURL; oQkY@)3.w
this.nStartPos = nStart; #kuk3}&
this.nEndPos = nEnd; <MPoDf?h
nThreadID = id; )bM #s">Y
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @rTAbEk{U
} @\!9dK-W
)k@+8Yfa1p
Sb9In_* 0
public void run() iTt#%Fs)4M
{ e^Ds|}{V
while(nStartPos < nEndPos && !bStop) WLb*\
{ #*g.hL<
`#m>3
9O%4x"*PO
try{ )ny,vcU]
URL url = new URL(sURL); )ZU=`!4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L 1fK
httpConnection.setRequestProperty("User-Agent","NetFox"); V?k"BU
String sProperty = "bytes="+nStartPos+"-"; %/^kr ZD
httpConnection.setRequestProperty("RANGE",sProperty); Xgy)Z:R
Utility.log(sProperty); N'#Lb0`B
CD]2a@j{
&.\|w
InputStream input = httpConnection.getInputStream(); (,J`!Y hS
//logResponseHead(httpConnection); +hz^( I7
)>! IY Q
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byte[] b = new byte[1024]; lO+<T[
int nRead; Rv ]?qJL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Lnk!zj
{ bEXm@-ou
nStartPos += fileAccessI.write(b,0,nRead); .Y.{j4[LQ
//if(nThreadID == 1) )A`Zgg'L7D
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]Tje6iF
} gAx8r-` `
) OqQz7'
-*?Y4}mK
Utility.log("Thread " + nThreadID + " is over!"); 2Qoj>Wy{
bDownOver = true; A0NNB%4|/
//nPos = fileAccessI.write (b,0,nRead); tGKIJ`w*h
} ~~.v*C[
catch(Exception e){e.printStackTrace ();} 4b"%171
} C~2/ 5
} [":[\D'
:qx>P_&y}z
R|Oy/RGY$
//打印回应的头信息 5 i1T?
public void logResponseHead(HttpURLConnection con) !~'\Ey
{ Kb_R "b3v
for(int i=1;;i++) V/0?0VKG
{ IH$R XGL
String header=con.getHeaderFieldKey(i); Y:nF.An3
if(header!=null) =jik33QV<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ,RkL|'1l
Utility.log(header+" : "+con.getHeaderField(header)); x04JU$@
else L"i B'=
break; dBV^Khf J
} x 5u.D^
} C +-<
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$z7[RLu0!
public void splitterStop() 9`8\<a'rU
{ +[ _)i9a
bStop = true; 8F$b/Z
} !;SpQ28
WC!bB
*&j)"hX
} \ B~9Ue!
zS Yh ?NB5
LhZWK^!{S
/* _v=@MOI/J
**FileAccess.java ]Q\Ogfjp
*//文件访问(定位，写) D_6GzgZ
package NetFox; :x*8*@kC
import java.io.*; ~P*t_cpZ
lN,8(n?g
)OqN\
public class FileAccessI implements Serializable{ {cF7h)j
\?,'i/c-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _tfZg /+)
RandomAccessFile oSavedFile; Fj9/@pe1
long nPos; @<]xbWhuw
XpzdvR1
r)|X?
public FileAccessI() throws IOException &jgpeFiiC
{ >G2o
this("",0); +#5nk,1c>
} v>3)^l:=Y*
?Z@FxW
XA~Rn>7&H
public FileAccessI(String sName,long nPos) throws IOException <zN
{ ;lST@>
oSavedFile = new RandomAccessFile(sName,"rw"); z_#B 4
this.nPos = nPos; uQN8/Gy*J
oSavedFile.seek(nPos); 47_4`rzy;
} @GGzah#
9l+`O0.@
QD LXfl/
public synchronized int write(byte[] b,int nStart,int nLen) 9&A-o
{ 0fvQPs!O
int n = -1; 6h N~<
try{ Z*d8b
oSavedFile.write(b,nStart,nLen); #&.&Uu$
n = nLen; d:0RDK-}s
} 2}u hPW+
catch(IOException e) Fzk
{ Y[gj2vNe4g
e.printStackTrace (); ?JTy+V2t
} f>JuxX\G
pN<wO1\9
pb`F_->uq
return n; 4Vj|k\vE4
} Lj"~6l`)
X75>C<
uROt h_/
} tRYMK+
oC>QJ(o,8
=:aH2T*
/* eL9RrSXz
**SiteInfoBean.java v*5n$UFV
*/ W|@EKE.k
package NetFox; (US]e un
OpY2Z7_
Wy%q9x]}
public class SiteInfoBean { QP|Ou*Qm)
=+q9R`!L]
zIWw055W
private String sSiteURL; //Site's URL SsDz>PP
private String sFilePath; //Saved File's Path RqW ZhHI1M
private String sFileName; //Saved File's Name o)KF+[^
private int nSplitter; //Count of Splited Downloading File DO(-)izC
Vg/{;uLAe
S\GC^ FK
public SiteInfoBean() hS&,Gm`^
{//nSplitter的缺省值为5 L)VEA8}
//default value of nSplitter is 5 )((Jnm D
this("","","",5); 2%N$Y]
} #NVtZs!V/
U9IP`)z_5t
;]?1i4p)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 693J?Yah[
{ I#Ay)+D
sSiteURL= sURL; B:5(sK
sFilePath = sPath; w!)B\l^+c
sFileName = sName; :(?joLA
this.nSplitter = nSpiltter; S#qd#Zk|Y
c&2ZjM
eX9{wb(
} T[s_w-<7$
cD^n}'ej
I,vy__sZ
public String getSSiteURL() 7/NXb
{ [P2$[|IM
return sSiteURL; S =q.Y
} 3q
[AQ6ads)
+ex@[grsGT
public void setSSiteURL(String value) Mn$TWhg'
{ aQwcPy|1R
sSiteURL = value; bC?uyo"
} F ^Rt 6Io
>/1N#S#9
%\=5,9A\
public String getSFilePath() h@FDP#H
{ xh[Mmq/R
return sFilePath; HDYr?t~V
} H r?G_L
*. l,_68
O^hWG ~o
public void setSFilePath(String value) 4H8vB^
{ AD=@
sFilePath = value; r]?ZXe$;
} i;c0X+[
D61CO-E(D
Z5;1ySn{
public String getSFileName() )I{41/_YA
{ /ZZo`
return sFileName; JPS22i)P
} _)Q)tOW
ed4:r/Dpo
ji<b#YO4
public void setSFileName(String value) ws Lg6
{ `GS!$9j
sFileName = value; mJRvC%
} <Bb$d@c
y.2_5&e/
+:?-Xd:p
public int getNSplitter() 8I$B^,N
{ @Z~lM5n$8
return nSplitter; BKfcK>%g
} |E0>-\6
!Sfy'v.
R!;tF|]
public void setNSplitter(int nCount) K>6#MI
{ {&8-OoH ~
nSplitter = nCount; _KC)f'Cx
} Oga0CR_
} }9t$Cs%
IBb3A
"DM$FRI0
/* Rv ?Go2
**Utility.java Q^/66"Z:Z
*/ AZt~ \qf
package NetFox; /4+M0Pl
<splLZW3k
JLm0[1Lzd
public class Utility { 12DMb9_rp
[t5:4 Iq
1@RctI_}
public Utility() S9}P5;u
{ BbUZ,X*Y
\ }>1$kH;
XWZ *{/u
} ^;n,C+
bEP-I5j1t
//线程睡眠 ?dlQE,hB$
public static void sleep(int nSecond) y562g`"U
{ Teu4;
try{ qyGVyi3
Thread.sleep(nSecond); pL8+gL
} YuSe~~F)j
catch(Exception e) w'K\}G~
{ 1uz9zhG><
e.printStackTrace (); Kc_QxON4
} YOwo\'|=
} (o)nN8
n^'ip{
//日志 .5|AX6p+^
public static void log(String sMsg) qPuxYU
{ ]=of=T:
System.err.println(sMsg); ]H0BUg
} oQI3Yz
sguE{!BO
+u' ?VBv
public static void log(int sMsg) U0t/(Jyg
{ ?~uTbNR
System.err.println(sMsg); a{^[<
} > nY<J
} 9"1 0:\U
_$PZID
,n TC7V
/* 3&_O\nD
**TestMethod.java db`xlvrCY
*/ Mz# &"WjF
package NetFox; 5_ -YF~
5 :6^533]
H`CDfTy
public class TestMethod { Fx2 KRxk
CdlE"Ye
"{105&c\
public TestMethod() ~Tq `c
{ ///xx/weblogic60b2_win.exe >Jt,TMMlt
try{ 6|wiZw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /cF 6{0XS9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {ER! 0w/
SiteFileFetch fileFetch = new SiteFileFetch(bean); SY>i@s+ML
fileFetch.start(); 4]A2Jl E
} J?Brnf.
catch(Exception e){e.printStackTrace ();} /c'3I
wO&`3Q3~$
^;@q^b)ZP
} 7SLJLn3d
Ac'[(
{[hH: \
public static void main(String[] args) *Uie{^p?
{ <:0649ZB
new TestMethod(); U:m[* }+<
} fs+l
} wV-1B\m
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