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)); EwG+' nlE
} d(t)8k$
for(int i=0;i<nEndPos.length-1;i++) X~m57bj
{ "24d:vf\
nEndPos = nStartPos[i+1]; }Y.@:v j
} j,].88H
nEndPos[nEndPos.length-1] = nFileLength; }P%gwgPK
} 4J,6cOuW4
} @>U9CL"
+,"[0RH
0P$19TN
//启动子线程 yg}L,JJU<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {=I,+[(
for(int i=0;i<nStartPos.length;i++) 'p[6K'Uq5
{ _6.@^\;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `::j\3B&Y-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h\#4[/
nStartPos,nEndPos,i); 6C.!+km
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vt zSM%=
fileSplitterFetch.start(); UE_>@_T
} ;QuxTmWp^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tZ=|1lM
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }T902RL0
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~qb?#IY]`
nEndPos = " + nFileLength); O+XQP!T
// fileSplitterFetch[nPos.length-1].start(); uq:'`o-1
i)@vHh82
i-0AcN./p
//等待子线程结束 "OUY^ cM
//int count = 0; cQh{z8Bf?<
//是否结束while循环 "[A&S!
boolean breakWhile = false; &C,]c#-+
T;3~teVYB
Ca"i<[8
while(!bStop) jvd3_L-@E<
{ !5m~qet.
write_nPos(); 35-FD{
Utility.sleep(500); Jz;`L3m
breakWhile = true; QKz2ONV=)
k3OnvnJb
e!i.u'z
for(int i=0;i<nStartPos.length;i++) AsZyPybq
{ nYRD>S?uz
if(!fileSplitterFetch.bDownOver) Vyx&MU.-J
{ `~=Is.V[
breakWhile = false; f}FJR6VO
break; U_B`SS
} gJOswN;([
} nzYFa J+
if(breakWhile) +xmZK<{<
break; ^eYJ7&t
WWTJ%Rd|
QQ,w:OjA0
//count++; \v9<L'NP)
//if(count>4) hi]\M)l&x
// siteStop(); kS7T'[d
} QPF[D7\
>yqL
yFP#z5G
System.err.println("文件下载结束！"); 1G8t=IA%D
} RzSN,bLR
catch(Exception e){e.printStackTrace ();} LyXABQ]
} tX}Fb0y
b}q,cm
-3b0;L&4>x
//获得文件长度 .^1=*j(;
public long getFileSize() f.r-,%^6{
{ Nb{oH+$b
int nFileLength = -1; /L[:C=u
try{ 2Z..~1r
URL url = new URL(siteInfoBean.getSSiteURL()); 4';['
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); veE8 N~0N.
httpConnection.setRequestProperty("User-Agent","NetFox"); K<_H`k*x
+V\NMW4d
#wm)e)2@
int responseCode=httpConnection.getResponseCode(); N4mQN90t
if(responseCode>=400) |s`q+ U-
{ ]g+(#x_.?
processErrorCode(responseCode); D{z=)'/F
return -2; //-2 represent access is error ~d5{Q?T)
} T +4!g|Y
>"nk}@
h/w- &7t
String sHeader; n2O7n@8
>\p}UPx
ZyWC_r!
for(int i=1;;i++) K|1^?#n
{ (c*Dvpo1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,zyrBO0 Eq
//Utility.log(in.readLine()); \)"qN^we
sHeader=httpConnection.getHeaderFieldKey(i); Ua3ERBX{
if(sHeader!=null) %E!0,y,:
{ XF$C)id2p
if(sHeader.equals("Content-Length")) q B2#EsZ
{ =gqZ^v&5U
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &boBu^,94
break; nz&JG~Qfm
} tE>:kx0*3
} &\K#UVDyhh
else K^vMIoh
break; sR0nY8@F
} ^b.J z}
} Zj0&/S
catch(IOException e){e.printStackTrace ();} eK@Y] !lz
catch(Exception e){e.printStackTrace ();} 1|89-Ii]
8vP)qy8
`'QPe42
Utility.log(nFileLength); pVY.&XBZ$
rYqvG
i xyjl[G
return nFileLength; +$'/!vN
} :4Vt
Z~gqTB]H
~!OjdE!u
//保存下载信息（文件指针位置） 'mM5l*{
private void write_nPos() btE+.V
{ M/qiA.C@W
try{ {Q"<q`c
output = new DataOutputStream(new FileOutputStream(tmpFile)); zYNJF>^<
output.writeInt(nStartPos.length); s5dh]vNN
for(int i=0;i<nStartPos.length;i++) 5*r6#[S\
{ "8I4]'
// output.writeLong(nPos); wtKh8^:YD
output.writeLong(fileSplitterFetch.nStartPos); Ww~0k!8,t
output.writeLong(fileSplitterFetch.nEndPos); 90!Ib~7zH
} 6M9rC[h\
output.close(); %Z? o]
} !|/fVWH
catch(IOException e){e.printStackTrace ();} XTJ>y@
catch(Exception e){e.printStackTrace ();} AQ5v`xE4
} T_-MSXhA
+*q@=P,
[8w2U%}]
//读取保存的下载信息（文件指针位置） _<7FR:oBZ
private void read_nPos() YovY0nO
{ 4@I]PG
try{ O#\>j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 96avgyc
int nCount = input.readInt(); (YOgQ)},
nStartPos = new long[nCount]; d8#j@='a*
nEndPos = new long[nCount]; !)=o,sVA
for(int i=0;i<nStartPos.length;i++) Dhoj|lc
{ +q$|6?
nStartPos = input.readLong(); Tjqn::~D
nEndPos = input.readLong(); Cs{f'I
} P>-,6a>
input.close(); `,Gk1~Wv
} O@rb4(
catch(IOException e){e.printStackTrace ();} ]Yex#K
catch(Exception e){e.printStackTrace ();} Hi9z<l=$
} |Y11sDa9h
:N}KScS|Wa
Cj+=9Dc
private void processErrorCode(int nErrorCode) v_0!uT5~NE
{ l0{DnQA>I
System.err.println("Error Code : " + nErrorCode); dk/*%a +
} sBnPS[Oo
,be?GAq
"S:N-Tf%U
//停止文件下载 H)Ge#=;ckQ
public void siteStop() (?y2@I}
{ c^IEj1@}'?
bStop = true; 17oxD
for(int i=0;i<nStartPos.length;i++) zQ}N mlk
fileSplitterFetch.splitterStop(); ,v_r$kh^
w>_EM&r6~u
em}Qv3*#
} {2^@jD
} C:MGi7f
//负责部分文件的抓取 jqWvLBU!
**FileSplitterFetch.java u$8MVP
*/ g"S+V#R
package NetFox; -<]_:Kf{;&
bU`yymf{L
oH0F9*+W
import java.io.*; [)>8z8'f
import java.net.*; +lJ]-U|P
RLNuH2y;
@(fY4]K
public class FileSplitterFetch extends Thread { Zb;$ZUWQX
%nf=[f
[Od9,XBa
String sURL; //File URL :~R Fy?xRa
long nStartPos; //File Snippet Start Position 4^_Au^8R(
long nEndPos; //File Snippet End Position 5G;^OI!g
int nThreadID; //Thread's ID [(EH
boolean bDownOver = false; //Downing is over |o=ST
boolean bStop = false; //Stop identical luk2fi<$
FileAccessI fileAccessI = null; //File Access interface F{~r7y;0
<SdJM1%Qo
p+UHJ&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException FKnQwX.0
{ -01 1U!
this.sURL = sURL; 6-14Htsk6
this.nStartPos = nStart; y"p-8RVk{
this.nEndPos = nEnd; )h_7 2
nThreadID = id; X]U"ru{1q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4eL54).1O
} >@"3Q`
o\;"|O}
^^3va)1{!
public void run() !_H8Q}a
{ tSc>@Q_|
while(nStartPos < nEndPos && !bStop) A6y~_dt
{ C"Q=(3
q=% C (
B "F`OS[
try{ Yn]yd1
URL url = new URL(sURL); I+j|'=M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4\SBf\ c
httpConnection.setRequestProperty("User-Agent","NetFox"); )F#<)Evw
String sProperty = "bytes="+nStartPos+"-"; r2F
httpConnection.setRequestProperty("RANGE",sProperty); t,1!`/\
Utility.log(sProperty); qb&NS4#
;E? hz
v\9,j
InputStream input = httpConnection.getInputStream(); .Jat^iFj0
//logResponseHead(httpConnection); y_4krY|Zx
%OTA5
MD ?F1l"}%
byte[] b = new byte[1024]; s.I1L?s1w?
int nRead; K9O,7h:x
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BOiz ~h6
{ NuS|X
nStartPos += fileAccessI.write(b,0,nRead); iraRB~
//if(nThreadID == 1) h[ZN >T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0B$7S,2
} EfBVu
h;ol"
n:^"[Le
Utility.log("Thread " + nThreadID + " is over!"); JfP\7
bDownOver = true; _`X#c-J
//nPos = fileAccessI.write (b,0,nRead); @U /3iDB\
} Y0u'@l_[F
catch(Exception e){e.printStackTrace ();} m~j\?mb{+
} l@Eq|y,
} Ij6Wz.*
rv%ye H
+/!=Ub[:U
//打印回应的头信息 kF+}.x%
public void logResponseHead(HttpURLConnection con) X#kjt)W
{ `l gjw=
for(int i=1;;i++) ,y8I)+
{ rTsbP40
String header=con.getHeaderFieldKey(i); ^`jZKh8)h
if(header!=null) |DFvZ6}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H?`)[#
Utility.log(header+" : "+con.getHeaderField(header)); QLB1:O>
else # +QWi0B
break; -#S)}NEn
} C7jc6(>m
} yK&*,J |
s7.p$r
N7~)qqb
public void splitterStop() s=nVoc{Yt
{ /[20e1 w!
bStop = true; gP%|:"
} X@yr$3vC
_Vo)<--+I
W3jXZ>
} `dgM|.w5=
PHRGhKJW})
$/, BJ/9
/* ib(>vp$V
**FileAccess.java L8bI0a]r"*
*//文件访问(定位，写) _^6|^PT.
package NetFox; ]<8B-D?Z
import java.io.*; @@%i(>4Z
7>'uj7r]=
H:q)^$s
public class FileAccessI implements Serializable{ jF38kj3O7
n%0]V Xx#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 HBh` 2Q
RandomAccessFile oSavedFile; f=:3!k,S
long nPos; 1jH7<%y
4?>18%7&
@cuD8<\i
public FileAccessI() throws IOException Gh]_L+
{ )YzHk ;(
this("",0); \Y!T>nWn)I
} *<*0".#
=zeFK_S!
f{y]
public FileAccessI(String sName,long nPos) throws IOException Si?$\H*:
{ a -xW8
oSavedFile = new RandomAccessFile(sName,"rw"); ]Q6+e(:~ZH
this.nPos = nPos; )p$\gwr=2
oSavedFile.seek(nPos); QU^/[75Ea0
} *2JH_Cj`
@gt)P4yE
<u/a`E?
public synchronized int write(byte[] b,int nStart,int nLen) I86e&"40
{ "sF Xl
int n = -1; e#>tM
try{ iD>G!\&
oSavedFile.write(b,nStart,nLen); cPpu
n = nLen; UF@IBb}0
} 33Ssylno
catch(IOException e) [096CK
{ Gs[Vu@*
e.printStackTrace (); 6(>3P
} 5^)?mA
+"]oc{W!
oi7 3YOB
return n; Q`H# fS~
} 1#grB(p?
p/r~n'g$
'UY[ap
} +"'F Be
C&=x3Cz
n vm^k
/* 2 9q?$V(
**SiteInfoBean.java "Dyym<J
*/ sz'p3
package NetFox; E@:Q 'g%
wD`[5~C{
Yt -W1vl
public class SiteInfoBean { nz^nptw
/:U1!9.y
5N\+@grp
private String sSiteURL; //Site's URL :]'q#$!
private String sFilePath; //Saved File's Path ;t}'X[U
private String sFileName; //Saved File's Name sF y]+DB
private int nSplitter; //Count of Splited Downloading File ~%`EeJwT
M~-h-tG
C1 W>/?XC
public SiteInfoBean() Y+FP
{//nSplitter的缺省值为5 ugno]5Ni
//default value of nSplitter is 5 [q'eENG
this("","","",5); b7bSTFZxC
} ,s0 9B
D}MoNE[r
f3!n$lj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +kM\ D~D1
{ *|oPxQCtK
sSiteURL= sURL; 6z Ay)~
sFilePath = sPath; |"Z-7@/k$i
sFileName = sName; Mq@}snp"S
this.nSplitter = nSpiltter; 3Y`>6A=
|) O):
HcA[QBh
} okz]Qc>G
WHP;Neb6
8 }-7{
public String getSSiteURL() (-\]A|
{ |CwG3&8
return sSiteURL; bo1I&I
} gGI8t@t:
N`HSE=u>
JA<~xo[Q9
public void setSSiteURL(String value) ;|!MI'Af
{ ;1@C_5C
sSiteURL = value; dMJ!>l>2
} [t{](-
2 5Q+1
12lEs3
public String getSFilePath() 6 Uw;C84!
{ dQ<(lzS~
return sFilePath; 0R|K0XH#$
} ,E?4f @|X
\!<"7=(J{4
Fj^AWv^/
public void setSFilePath(String value) y@A6$[%(E|
{ !!WJn}
sFilePath = value; ^wJEfac
} ,]7XMU3
~M*gsW$
`VZZ^K9zR
public String getSFileName() WYLX?x
{ P?J kP
return sFileName; #V[SQ=>x[
} skR,-:"8
PBrnzkoY
o@3B(j;J`
public void setSFileName(String value) pds*2p)2
{ hJ[UB
sFileName = value; HN68!v}C|
} Lm|al.Z
M"(6&M=?
9|=nV|R'6
public int getNSplitter() kOipH |.x
{ t77'fm
return nSplitter; ,QvYTJ{
} o1k#."wHr
X$V|+lTk
-B9S}NPo
public void setNSplitter(int nCount) ffk4mhH
{ <d"Gg/@a
nSplitter = nCount; j#3m|dQ
} hVUIBJ/5(-
} "PzP;Br
3dG4pl~
lFfXWNb
/* "IwM:v
**Utility.java s;1e0n
*/ _{Y$o'*#I
package NetFox; Spgg+;9
Hku=pr3Gn
_Adsq8sFW
public class Utility { Ae49n4J
!ZrB^?sO
Qra>}e%*
public Utility() "={L+di:M
{ H]Wp%"L
V]c5 Z$Bd
L~eAQR
} LgHJo-+>
F=}Z51|:~
//线程睡眠 |C D}<r(N
public static void sleep(int nSecond) tcA;#^jc
{ }q'WC4.
try{ hhmGv9P
Thread.sleep(nSecond); z*LiweR-
} ]yLhJ_^
catch(Exception e) 0=;YnsY
{ ^,V[nfQR
e.printStackTrace (); U9#WN.noG
} #T\
} / Z!i;@Wf
GBbhar},g
//日志 &p"(-
public static void log(String sMsg) G9RP^
{ C4NRDwU|.
System.err.println(sMsg); U)[ty@zyF
} c_1/W{
]US[5)EL-
!Iq{ 5:
public static void log(int sMsg) Gzm$OHbn
{ Z;b+>2oL
System.err.println(sMsg); 1S%}xsR0
} VJ{pN~_1
} rkYjq4Z@
6c<ezEJ
7>-yaL{
/* iV hJH4
**TestMethod.java Np)aS[9W
*/ K{b-TT 4
package NetFox; >V!LitdJ
G;]:$J
8#f$rs(}
public class TestMethod { @E_zR
jJ++h1 K
~7SH4Cr
public TestMethod() Z2p> n`D
{ ///xx/weblogic60b2_win.exe e|'N(D}h*
try{ }*kJ-q&0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); FA$zZs10\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); )saR0{e0N
SiteFileFetch fileFetch = new SiteFileFetch(bean); RP` `mI
fileFetch.start(); +Me2U9
} XDLEVSly7
catch(Exception e){e.printStackTrace ();} =n0*{~r
9L)L|4A.l
:oa9#c`L
} Dip*}8$o(w
1D{#rA.X
o3h-=t
public static void main(String[] args) D1X{:#|
{ (pYYkR"
new TestMethod(); Lk.h.ST
} crn k|o
} 6Rz[?-mkLO
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