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)); z Ey&%Ok
} 9i@*\Ada
for(int i=0;i<nEndPos.length-1;i++) z;)% i f6
{ $U1'n@/J
nEndPos = nStartPos[i+1]; TzjZGs W[V
} 08Gr
nEndPos[nEndPos.length-1] = nFileLength; #v1 4"sZ}
} uM$=v]e^4
} <=lP6B
x.aUuC,$x
n=~?BxB
//启动子线程 Iq9+
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ]d0Dd")n
for(int i=0;i<nStartPos.length;i++) v%r!}s
{ XT\;2etVL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), o3yZCz
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), #&^+hx|
nStartPos,nEndPos,i); :Wln$L$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pc #^{-
fileSplitterFetch.start(); ?hO*~w;UU|
} +!rK4[W'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), - >2ej4C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /V^S)5r
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6BMn7m?
nEndPos = " + nFileLength); 8LOzL,Ah
// fileSplitterFetch[nPos.length-1].start(); R_csKj
&,+ZNA`P
iw%DQ }$
//等待子线程结束 yTk9+>
//int count = 0; p[RD[&#b
//是否结束while循环 h6#
boolean breakWhile = false; Jx_4:G
Q{RHW@_/
GIp?}tM
while(!bStop) 1FuChd
{ V6c?aZ,O
write_nPos(); ({)_[dJ'
Utility.sleep(500); q /#O :Q
breakWhile = true; j_Fr3BWS
~0`Pe{^*
;YB8X&H$
for(int i=0;i<nStartPos.length;i++) DZvpt%q
{ h<uQ~CQg
if(!fileSplitterFetch.bDownOver) {)G3*>sG3
{ B$HQFdTli
breakWhile = false; oR~+s&c
break; 8.@yD^'
} Zhw _L
} u%2u%-w
if(breakWhile) E:7vm@+
break; PUI.Un2C_
)]>9\(
$*tuv?
//count++; H_x35|"
//if(count>4) 0-QkRr_I
// siteStop(); .UJk0%1
} Z"P{/~HG
o)NWsUXf
G|o-C:~
System.err.println("文件下载结束！"); E;N+B34
} #)XO,^s.
catch(Exception e){e.printStackTrace ();} r`lgK2r\
} sbgRl%
]O 2_&cs
2)G ZU
//获得文件长度 >$}nKPC,Y
public long getFileSize() lcih [M6z
{ !0cfz5t
int nFileLength = -1; yfV{2[8ux
try{ P0W%30Dh
URL url = new URL(siteInfoBean.getSSiteURL()); pt=[XhxC(>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p@P[pzxI
httpConnection.setRequestProperty("User-Agent","NetFox"); 9[:nWp^
eudPp"Km
-"<eq0
int responseCode=httpConnection.getResponseCode(); MjHeUf
if(responseCode>=400) GSl\n"S]=
{ lp4sO#>`
processErrorCode(responseCode); l_DPlY
return -2; //-2 represent access is error BWd?a6nU}
} U9Y'eP.2
(|Xf=q,Le
A1i-QG/6
String sHeader; l*h6JgU
EQg 6*V
Yd]f}5F
for(int i=1;;i++) b\}`L"
{ Vb/J`
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Y5K!DMKY
//Utility.log(in.readLine()); :5;[Rg5 2
sHeader=httpConnection.getHeaderFieldKey(i); lG q;kIQ
if(sHeader!=null) 7m8L!t9
{ )Y)7p//
if(sHeader.equals("Content-Length")) X~lOFH;}q
{ cLamqZf3
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fE7Kv_N-%
break; vG<Mz?wr
} 1V)0+_Yv
} 5o&L|7]
else <{e0i
break; (RGl, x:
} 1`b?nX
} 9;.dNdg>
catch(IOException e){e.printStackTrace ();} LM0TSB?
catch(Exception e){e.printStackTrace ();} Lc+)#9*d
NJn~XCq
OS,-dG(
Utility.log(nFileLength); Rnj2Q!C2
TLi0*)}
ci,o'`Q
return nFileLength; |U12fuQ
} |`#[jHd
yl|+D]
|IZG`3
//保存下载信息（文件指针位置） @Yy=HV
private void write_nPos() L{aT"Of{X
{ }eBy p
try{ I#9A\.pO
output = new DataOutputStream(new FileOutputStream(tmpFile)); !SVW}Q=5#
output.writeInt(nStartPos.length); =n%?oLg^
for(int i=0;i<nStartPos.length;i++) BC&Et62*
{ (gz|6N
// output.writeLong(nPos); J0^p\mG
output.writeLong(fileSplitterFetch.nStartPos); _)lK.5
output.writeLong(fileSplitterFetch.nEndPos); uI.4zbgl[
} C!v0*^i
output.close(); ?zxKk(J
} "x&H*"
catch(IOException e){e.printStackTrace ();} s|dL.@0,L
catch(Exception e){e.printStackTrace ();} =T;%R^@
} ZO:{9vt=/
k?1cxY s
;sb0,2YyP
//读取保存的下载信息（文件指针位置） @ -g^R4e<
private void read_nPos() O`H[,+vm[
{ +HUI1@ql
try{ (,HAOs
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Xo}w$q5
int nCount = input.readInt(); eF!c< Kcr
nStartPos = new long[nCount]; E/Y.f
nEndPos = new long[nCount]; \U p<m>3\
for(int i=0;i<nStartPos.length;i++) bMf+/n
{ ;v#~o*
nStartPos = input.readLong(); ;z!~-ByzL
nEndPos = input.readLong(); (Z sdj
} Ws}u4t
input.close(); 7-bU9{5
} $ 5
catch(IOException e){e.printStackTrace ();} .GLotc
catch(Exception e){e.printStackTrace ();} +n1}({7m
} 1,BtOzuRo
j @sd x)1+
7vgz=- MZ#
private void processErrorCode(int nErrorCode) {U7j
{ 0p:n'P
System.err.println("Error Code : " + nErrorCode); e$ E=n
} V<P@hAAr
h?fv:^vSi
i7:j(W^I8
//停止文件下载 no^I![_M
public void siteStop() n(-XI&Kn
{ r's4-\
bStop = true; 8V.x%T
for(int i=0;i<nStartPos.length;i++) %]RzC`NZ
fileSplitterFetch.splitterStop(); N!^U{;X7/
|\Jpjm)?
q48V|6X'q
} AgO:"'c
} /tx_I(6F?|
//负责部分文件的抓取 wIL5-k,
**FileSplitterFetch.java :!J!l u
*/ `[/BG)4
package NetFox; bZ:w_z[3=
|Ax~zk;
&\`=}hB
import java.io.*; &`0heJ 5Yn
import java.net.*; *}A J7]
KGzBK:
:1=mNrg
public class FileSplitterFetch extends Thread { EivZI<<a
M*{EK
FG1$_zN |
String sURL; //File URL _K8ob8)m
long nStartPos; //File Snippet Start Position !SKEL6~7
long nEndPos; //File Snippet End Position X{<j%PdC
int nThreadID; //Thread's ID |Zncr9b
boolean bDownOver = false; //Downing is over GYyP+7K4l[
boolean bStop = false; //Stop identical zT`LPs6T
FileAccessI fileAccessI = null; //File Access interface ci6j"nKci
x}].lTjD
I4gyGg$H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException B7_:,R.l
{ jvCk+n[
this.sURL = sURL; "PLZZL$+
this.nStartPos = nStart; dGTAZ(1W
this.nEndPos = nEnd; %)u5A!"
nThreadID = id; gfFP-J3cN
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )!e-5O49r
} Ri"3o
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rW&8#&
public void run() S_ e }>-
{ 7Oru{BQ">
while(nStartPos < nEndPos && !bStop) }`\+_@w
{ gNo.&G [
/0\m;&
{{SeD:hx
try{ ^t?P32GJ
URL url = new URL(sURL); Oy&Myjny<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lpj$\WI=
httpConnection.setRequestProperty("User-Agent","NetFox"); f'TdYG
String sProperty = "bytes="+nStartPos+"-"; 9#@dQ/*
httpConnection.setRequestProperty("RANGE",sProperty); 39BGwKXb
Utility.log(sProperty); K.dgQ-vn
-_4U+Cfmtl
[x'xbQLGd
InputStream input = httpConnection.getInputStream(); vB#&XK.aW
//logResponseHead(httpConnection); W,}HQ
$ GL$ iA
KaZ$!JfT
byte[] b = new byte[1024]; AFF7fK
int nRead; /t01z~_
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *U)!9DvA
{ ?6; +.h\
nStartPos += fileAccessI.write(b,0,nRead); K#}DXq
//if(nThreadID == 1) wMT?p/9Blm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k]] (I<2
} #7/_Usso
#y~^!fdp9
!/BXMj,=
Utility.log("Thread " + nThreadID + " is over!"); ezY _7
bDownOver = true; bN8GRK )
//nPos = fileAccessI.write (b,0,nRead); ~Q0gSazXFt
} n[[rI0]g
catch(Exception e){e.printStackTrace ();} ?*tb|AL(R
} .u>IjK^
} 1aS[e%9Mg
o=X6PoJN_
? !MDg_oHd
//打印回应的头信息 \8'fy\
public void logResponseHead(HttpURLConnection con) q1;}~}W;z4
{ |nk&ir6
for(int i=1;;i++) =P<gZ-Cm
{ $RuJm\f
String header=con.getHeaderFieldKey(i); rLw,?
if(header!=null) NU-({dGK}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ik=~`3Zp0
Utility.log(header+" : "+con.getHeaderField(header)); /o*r[g7<
else ~B'K_#
break; XnHcU=~q
} h1^q};3!W\
} )F,H(LblH
jV;&*4if
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public void splitterStop() FYFP6ti
{ ]2T=%(*
bStop = true; @V Bv}Jo
} TartV3;`
uHkL$}C
U+3,(O
} ;\DXRKR
<(TTYf8lS
(f,D$mX
/* }eXzs_
**FileAccess.java }nvHEo
*//文件访问(定位，写) /d ?)
package NetFox; rDX_$,3L
import java.io.*; z_~5c
)q&=x2`
0zCe|s.S&
public class FileAccessI implements Serializable{ N|EH`eu^i
?%J{1+hY
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ,3Y~ #{,i
RandomAccessFile oSavedFile; :vz_f$=
long nPos; .Wv2aJq
<03@cs
qsk8#
public FileAccessI() throws IOException B @H.O!
{ , |CT|2D>
this("",0); T]l_B2.
} I2hX;pk,
R?a)2jl
I8;pMr6
public FileAccessI(String sName,long nPos) throws IOException X2hV)8Sk
{ !([Q1r{u
oSavedFile = new RandomAccessFile(sName,"rw"); (9]`3^_,J
this.nPos = nPos; ,R5NKWo
oSavedFile.seek(nPos); 3P-qLbJ
} lG;RfDI-
IT5AB?bxH
/-Y*V*E
public synchronized int write(byte[] b,int nStart,int nLen) ;Y5"[C9|
{ _Il/ i&
int n = -1; 7^P!@o$v!
try{ B<i)je!
oSavedFile.write(b,nStart,nLen); a1R2ocC
n = nLen; PdcF
} RbKAB8
catch(IOException e) Mt(wy%{zK
{ M)C.bo{p
e.printStackTrace (); }\k"azQ`
} ^o}!=aMr
NWd%Za5K;
( >zXapb2
return n; c+c3C8s*8
} <GC<uB |p
w'oP{=y[
SV}q8z\
} rC V&&09
9oKRnc
Nlemb:'eP3
/* 3&.?9
**SiteInfoBean.java gO_{(\w*
*/ s.&ewf\
package NetFox; TkXD#%nFY
a@$U?=\e
i$gm/ZO
public class SiteInfoBean { Sr Z\]
Vb*q^ v
H6X]D"Y,
private String sSiteURL; //Site's URL dIgaw;Ch]
private String sFilePath; //Saved File's Path ~n9BN'@x
private String sFileName; //Saved File's Name L!s/0kBg
private int nSplitter; //Count of Splited Downloading File s1.YH?A;
(NK$2A/p
RL7OFfMe
public SiteInfoBean() vY0C(jK
{//nSplitter的缺省值为5 mJe;BU"y]
//default value of nSplitter is 5 6C@,&2<yK
this("","","",5); v*`$is+
} UhQ[|c
XF(0>-
W8+Daw1Nr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) N+%E=D>
{ NPy{ =#k4
sSiteURL= sURL; y33+^
sFilePath = sPath; ;M}'\.
sFileName = sName; c'B6E1}sx
this.nSplitter = nSpiltter; 3on]#/"1b
58)`1p\c'
F!OVx<
} 0PO'9#
HTiqErD2_
|!:ImX@
public String getSSiteURL() ~&B{"d
{ @9~a3k|
return sSiteURL; VcKufV'
} n*~=O'
W<C \g~\
qXPjxTg{[
public void setSSiteURL(String value) ~H!s{$.5
{ M&o@~z0
sSiteURL = value; aZEi|\VU
} 4UD<g+|
YSERQo
}PdS?[R
public String getSFilePath() <+@?V$&
{ 9SF2
return sFilePath; l]D?S]{a
} ={,\6a|]:
bE:oF9J?
Kcv7C{-/
public void setSFilePath(String value) V)#se"GV
{ j]th6
sFilePath = value; OCmF/B_
} 4#Wczk-b
Z]f_?@0
))f%3_H
public String getSFileName() ~?i;~S
{ rmXxid
return sFileName; /.{4 KW5
} .U|irDO
#G2~#\
u:#+R_0#97
public void setSFileName(String value) \|9@*]6:
{ Im7<\ b@
sFileName = value; G?$|aQ0j
} H0<(j(JK
<>JN&#3?
[r,a0s
public int getNSplitter() MTJ ."e<B
{ X+zFRL%
return nSplitter; tSX<^VER7
} B1dVHz#
L1=+x^WQ
.%)FK#s-
public void setNSplitter(int nCount) ;Q"xXT`;:
{ xG:eS:iT
nSplitter = nCount; `B6~KZ
} U6^x(2De
} I^erMQn[ z
_~V7m
BoQLjS{kN
/* LVNq@,s
**Utility.java ?m.WqNBH7
*/ S9/oBxGN
package NetFox; G"w ?{W@
`x%v&>
jo 0 d#
public class Utility { )p*I(y
gB/4ro8
EC(,-sz\Z
public Utility() ZC}'! $r7
{ sb"z=4
So>P)d$8+
a@(4X/|
} DM {r<?V
W4n;U-Hb
//线程睡眠 ^Ud1 ag!-
public static void sleep(int nSecond) xs+pCK|
{ Ia_I~ U$
try{ | RMIV
Thread.sleep(nSecond); *J^l r"%c
} o5=1
catch(Exception e) ~uqpF-.
{ _<tWy+.
e.printStackTrace (); 1>hY!nG h
} hx|Cam"
} wdS4iQD
_dOR-<
//日志 fik*-$V`
public static void log(String sMsg) DUBEh@
{ =eG?O7z&
System.err.println(sMsg); l2&cwjc
} hP1}Do
8!8 yA
)1 ]P4
public static void log(int sMsg) UjCQ W:[
{ Ky"]L~8$
System.err.println(sMsg); +ob<? T
} g\9I&z~?
} _dQVundH
@JJ,$?
M"cB6{st[
/* ['9awgkr/
**TestMethod.java 0\fV'JDOR
*/ :[icd2JCw]
package NetFox; tBR"sBiws
Ik{[BRzUgt
\:>GF-Z(
public class TestMethod { \HR<^xY
"},0Cs
qg521o$*
public TestMethod() l!r2[T]I@7
{ ///xx/weblogic60b2_win.exe 5]C}044
try{ `re9-HM
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7G,{BBB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -M]NdgI
SiteFileFetch fileFetch = new SiteFileFetch(bean); <'s_3AC
fileFetch.start(); P .I<.e
} iWCR5c=
catch(Exception e){e.printStackTrace ();} Q[g>ee
zj~(CNE
O>8|Lc
} LOm*=MVex
UO3QwZ4j;
>%qk2h>
public static void main(String[] args) ,&+"|,m
{ Gyo[C98
new TestMethod(); }^T7S2_Qy
} =E{e|(1+u
} 6yDc4AX
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