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)); a&B@F]+
} +(h{3Y|
for(int i=0;i<nEndPos.length-1;i++) $rPQ%2eF4
{ .$ HE
nEndPos = nStartPos[i+1]; wM!dz&
} 2j$~lI
nEndPos[nEndPos.length-1] = nFileLength; Kr+#)S
} .L.9e#?3
} ?B<.d8i
Myh?=:1~(c
Raf-I+
//启动子线程 -f"{%<Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; X5+$:jq&
for(int i=0;i<nStartPos.length;i++) ix5<h }
{ Twk<<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ka$lNL3<j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), s$ ?;C
nStartPos,nEndPos,i); [ZS.6{vr
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mcxD#+H 3
fileSplitterFetch.start(); )QI#szv6
} 7nZ3u_~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), imyfki $B
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _Zxo<}w}y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >".@;
nEndPos = " + nFileLength); .>Fpk7
// fileSplitterFetch[nPos.length-1].start(); 877Kv);
'Qg.D88
&5QvUn
//等待子线程结束 dEam|
//int count = 0; %I@vMs^
//是否结束while循环 P|TM4i]
boolean breakWhile = false; nY,LQ0r
|Gr@Mi5
aTs9lr:
while(!bStop) )*aAkM
{ BqtN=
write_nPos(); p:3w8#)MZ
Utility.sleep(500); $ SZIJe"K
breakWhile = true; <Ik5S1<h$H
#It!D5A
lLI%J>b@
for(int i=0;i<nStartPos.length;i++) 6sT(t8[
{ Y[W]YPs
if(!fileSplitterFetch.bDownOver) JX`>N(K4\
{ BJ{?S{"6%G
breakWhile = false; oslj<
break; QRwOv
} im F,8'
} 6rlvSdB
if(breakWhile) ]hZk#rp}
break; bb$1zSA
E CPSE{
,Qj\_vr@
//count++; 8#HQ05q>
//if(count>4) 0f9U:)1z
// siteStop(); <}F(G-kV6
} )M8@|~~
zo@,>'m
gBZNO! a,d
System.err.println("文件下载结束！"); ;Hb"SB
} f4vdJ5pV
catch(Exception e){e.printStackTrace ();} \\35} 9
} XnRm9%
^MVOaV65
o5G]|JM_
//获得文件长度 *p|->p6,u
public long getFileSize() SKGnx
{ !e('T@^u6u
int nFileLength = -1; ,I:[-|Q
try{ boZ/*+t
URL url = new URL(siteInfoBean.getSSiteURL()); ;HiaX<O!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -?Cu-'
httpConnection.setRequestProperty("User-Agent","NetFox"); P@Vs\wAT
C#RueDa.
Pd~z%VoO
int responseCode=httpConnection.getResponseCode(); IG~Zxn1o
if(responseCode>=400) ]PbwG
{ v+CW([zAx#
processErrorCode(responseCode); PmT<S,}L
return -2; //-2 represent access is error o%K1!'
} pE$*[IvQ'
y8]vl;88yY
CS0q#?
String sHeader; 5'_:>0}
ML%JTx0+Z
0UQ DB5u
for(int i=1;;i++) m`jGBSlw_
{ ,QLy}=N
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); tR_DN
//Utility.log(in.readLine()); o_r{cnu
sHeader=httpConnection.getHeaderFieldKey(i); !ED,'d%J
if(sHeader!=null) 5xa!L@)`wF
{ Uh^j;s\y
if(sHeader.equals("Content-Length")) WL3J>S_
{ Y>K8^GS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B0^:nYko
break; w<Iq:3
} y tTppmJF
} ~xc0Ky?8
else ~!_UDD
break; 'Y/8gD~.
} .[Ny(X/]/}
} Gz7,g Y
catch(IOException e){e.printStackTrace ();} &+/$~@OK
catch(Exception e){e.printStackTrace ();} {<i(aq?
""jl
RI BB*
Utility.log(nFileLength); !X=93%
t`1~5#?Du(
" pL5j
return nFileLength; u3HaWf3
} Apkb!"}>
0- u,AD
pWKI^S
//保存下载信息（文件指针位置） #?~G\Ux0/
private void write_nPos() ,Uy~O(Ft
{ sO)!}#,
try{ zhU^~4F
output = new DataOutputStream(new FileOutputStream(tmpFile)); g5 y*-t
output.writeInt(nStartPos.length); o^u}(wZ{
for(int i=0;i<nStartPos.length;i++) =E&1e;_xlE
{ e(9K.3@{
// output.writeLong(nPos); mHNqzdaa
output.writeLong(fileSplitterFetch.nStartPos); ~~#/jULbV
output.writeLong(fileSplitterFetch.nEndPos); C6d#+
} ZV[-$
output.close(); &CfzhIi*!
} XL(2Qk
catch(IOException e){e.printStackTrace ();} &cf_?4
catch(Exception e){e.printStackTrace ();} F^Mt}`O
} h\8bo=
<p[RhP
M*F`s&vM
//读取保存的下载信息（文件指针位置） ' &Nv|v\V
private void read_nPos() N Q}5'
{ +sXnC\
try{ 07Oagq(
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5gwEr170
int nCount = input.readInt(); ) 3I|6iS
nStartPos = new long[nCount]; %i&\X[
nEndPos = new long[nCount]; P}-S[[b73s
for(int i=0;i<nStartPos.length;i++) :Y)G-:S+
{ T"E%;'(cp)
nStartPos = input.readLong(); 3.%jet1
nEndPos = input.readLong(); PH!rWR
} C0L(ti;
input.close(); yI's=Iu`
} &9xcP.3
catch(IOException e){e.printStackTrace ();} [8[`V)b
catch(Exception e){e.printStackTrace ();} fjS#
} ))J#t{X/8v
a1ai?},
[V;Q#r&+
private void processErrorCode(int nErrorCode) "-G&]YMl
{ ,D`\ RV
System.err.println("Error Code : " + nErrorCode); r7v1q
} Ft8ii|-
b>|d Q
dj3E20Ws
//停止文件下载 a<Ps6'
public void siteStop() B|rf[EI>
{ 9RY}m7
bStop = true; `_M&zN
for(int i=0;i<nStartPos.length;i++) kk aS&r>
fileSplitterFetch.splitterStop(); lI+KT_|L
Y IVN;:B.
_u;34H&/
} !r+SE
} <:~'s]`zf
//负责部分文件的抓取 qox@_
**FileSplitterFetch.java C6:; T%
*/ #:nds,
package NetFox; w5mSoKb
( z.\,M
R<ZyP~
import java.io.*; HuajdC~
import java.net.*; 1!2,K ot
mQ:5(]v
T?8N$J
public class FileSplitterFetch extends Thread { pg4jPuCM
wU5= '
QBTjiaYGa'
String sURL; //File URL Fpntd IU
long nStartPos; //File Snippet Start Position X6o iOs
long nEndPos; //File Snippet End Position :4S~}}N
int nThreadID; //Thread's ID 5~xv"S(E}
boolean bDownOver = false; //Downing is over 4+au6ABy
boolean bStop = false; //Stop identical /Y*6mQ:
FileAccessI fileAccessI = null; //File Access interface U\;mM\2rE
}I#,o!)Vd
M"z3F!-j
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException NSQf@o
{ Su[f"2oR
this.sURL = sURL; Y_M3-H=0
this.nStartPos = nStart; qF4pTQf
this.nEndPos = nEnd; 4:qM'z
nThreadID = id; zvh&o*\2<d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $lAhKpdlW
} (\$=+' hy
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public void run() ,F0bkNBG
{ /PtmJ2[
while(nStartPos < nEndPos && !bStop) <,(Ww
{ yyuf
8,&QY%8pX
#W=H)6
try{ qvN 5[rb
URL url = new URL(sURL); F$H^W@<w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OEj%cB!
httpConnection.setRequestProperty("User-Agent","NetFox"); 7a'@NgiGg
String sProperty = "bytes="+nStartPos+"-"; m*H6\on:
httpConnection.setRequestProperty("RANGE",sProperty); aZYs?b>Gm
Utility.log(sProperty); mX QVL.P\
5\P3JoH:Yg
~er4w+"
InputStream input = httpConnection.getInputStream(); OwG:+T_
//logResponseHead(httpConnection); (Qz| N
8nHFNOv6
.5?Md
byte[] b = new byte[1024]; >tVD[wVF0
int nRead; -nC!kpo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -$5nqaK?
{ 3']=w@~ O[
nStartPos += fileAccessI.write(b,0,nRead); Lw #vHNf6
//if(nThreadID == 1) aG/L'weR
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aT%6d@g
} 4Nz]LK%@
\J3n[6;
K@+(6\6I
Utility.log("Thread " + nThreadID + " is over!"); rJ_fg$.<
bDownOver = true; '5m`[S-IU
//nPos = fileAccessI.write (b,0,nRead); 'Lv>!s 7
} "r.eN_d
catch(Exception e){e.printStackTrace ();} ao.v]6a
} nXcOFU
} d"JI4)%
P*sb@y>}O
)K^5+oC17
//打印回应的头信息 \l9S5%L9
public void logResponseHead(HttpURLConnection con) CGN:=D<
{ b0"R |d[i
for(int i=1;;i++) +b6kU{
{ '9#h^.
String header=con.getHeaderFieldKey(i); 5$p7y:
if(header!=null) ]NgEN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Hze~oAP+
Utility.log(header+" : "+con.getHeaderField(header)); ]R s
else Ww$?X LF
break; f8?c[%br
} \3v}:E+3
} 2zN%Z!a#J
?.b.mkJ
l:rT{l=8*
public void splitterStop() a#:K"Mf.
{ ^zVBS7`J
bStop = true; .|9o`mF7
} !]z6?kUK
S`?cs^?
gw);b)&mx
} _f5n t:-
8]-c4zK
-?&s6XA%#
/* 5 NdIbC
**FileAccess.java iH""dtO
*//文件访问(定位，写) BSib/)p
package NetFox; 0"to]=
import java.io.*; nI6[y)j
*ioVLt,:R
qCaM]Y
public class FileAccessI implements Serializable{ D,Jyb0BW
-YHyJs-bU
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lGAKHCs
RandomAccessFile oSavedFile; />\6_kT
long nPos; K<Qy1y~[
X0QLT:J b
%;{Ro)03
public FileAccessI() throws IOException A#P]|i
{ 17{$D,P
this("",0); 4(FEfde=
} G`" 9/FI7
96$qH{]Ap
#+,O
public FileAccessI(String sName,long nPos) throws IOException 4BgrG[l)
{ /}=Bi-
oSavedFile = new RandomAccessFile(sName,"rw"); 0ynvn9@t
this.nPos = nPos; ,S7g=(27(
oSavedFile.seek(nPos); KDzTe9
} p:n.:GZ=y
EsR$H2"
'6&a8&:
public synchronized int write(byte[] b,int nStart,int nLen) 9s}y*Vp
{ BCtm05
int n = -1; 8S_v} NUm
try{ L&2 Zn{#`
oSavedFile.write(b,nStart,nLen); z1u1%FwOfM
n = nLen; {a `#O9
} ,m-/R
catch(IOException e) 8QYM/yAM
{ wpLC,
e.printStackTrace (); )m7 Yo
} U1wsCH3+n
*3>$f.QU
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return n; _;1H2o2f
} C_JDQByfL
JM-rz#;1
(?7=$z!h
} gZD,#D.hR
dUg| {l
GcL:plz
/* xJ(4RaP
**SiteInfoBean.java ;^K4kK&f
*/ Mmu>&C\
package NetFox; 7u9!:}Tu
Y79{v nlGk
f4TNy^-
public class SiteInfoBean { b\l +S2
`Ko6;s#
rcWr0q
private String sSiteURL; //Site's URL Jm l4EW7
private String sFilePath; //Saved File's Path (\=iKE4#
private String sFileName; //Saved File's Name OYsG#
private int nSplitter; //Count of Splited Downloading File v)a$;P%
},G>+ s8h
qd7 86~
public SiteInfoBean() $Jt+>.44
{//nSplitter的缺省值为5 [N-t6Z*
//default value of nSplitter is 5 X-&U-S;
this("","","",5); *mgK^9<
} |rDv!m
0Q1sJDa.
</OZ,3J=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) i!!1^DMrw
{ Nd"4*l;
sSiteURL= sURL; cF7efs8u
sFilePath = sPath; ;P{HePs=)
sFileName = sName; _26~<gU8
this.nSplitter = nSpiltter; ,%FBELqOW
?u`TX_OsB
IC6}s
} ; iK9'u
&!lGx7zf
D6KYkN(,v
public String getSSiteURL() Gg3cY{7
{ ~HH#aXh*
return sSiteURL; n2JwZ?
} uD2v6x236
Ris5)*7
g`}+K U
public void setSSiteURL(String value) $1h,<$5H
{ Y!8Ik(/~i
sSiteURL = value; -2dk8]KB]
} <3;Sq~^
) DzbJ}
,c%>M^d
public String getSFilePath() 7n1@m_7O
{ )K4A-9pC
return sFilePath; j(`L)/|O
} h7( R/Rf
p)$DpNL% p
#sOkD
public void setSFilePath(String value) ItZqLUJm
{ Fnnk}I}
sFilePath = value; 1%?J l~M
} pD+_ K
a/Cd;T2
.7ZV:m
public String getSFileName() k|^e=I
{ m{/?6h 1
return sFileName; b|cUKsL5
} ng-g\&-
z]NzLz9VfL
`|1#Vuk
public void setSFileName(String value) J~6-}z
{ >&|C E2'
sFileName = value; _7AR2
} BnLM;5 >
?(&)p~o
/5ngPHy&
public int getNSplitter() 36<PI'l#~
{ C>d_a;pX
return nSplitter; z8SrZ#mg
} /mb?C/CI
;$Eg4uX
@w)Vt$+b]
public void setNSplitter(int nCount) 1CkBfK
{ 0i[,`>-Av
nSplitter = nCount; /e^q>>z
} XNwZSW
} .kl _F7
]*8K4n G
.Y8z3O
/* cax]lO
**Utility.java Ylc[ghx
*/ )F\tU
package NetFox; bp06xHMu
ohFUy}y
TNA?fm
public class Utility { ~bp^Q| wM
jpl"KN?X
H1]An'qz,
public Utility() q;dg,Om
{ wt;7+
*CHLs^)
nQ*9|v4
} E,]G Ek
9'tElpDJ6#
//线程睡眠 o1j_5c PS
public static void sleep(int nSecond) CzF#feTA
{ Tl.dr
try{ _H:mBk,,
Thread.sleep(nSecond); zj ;'0Zu
} Y<'T;@
catch(Exception e) 6!|-,t><
{ 2]Nc@wX`p
e.printStackTrace (); SjT8eH #
} :27GqY,3sK
} 5",@!1ju
8Bvc#+B
//日志 iWbrX1 I+
public static void log(String sMsg) [NE:$@
{ _S43_hW
System.err.println(sMsg); _b+=q:$/
} jY>BU&
sx;7
WD=#. $z$
public static void log(int sMsg) aKkG[qN
{ >4gGb)
System.err.println(sMsg); Y)kO"
} :G/T{87H
} ,&Iw5E[
l.ri]e
|[ymNG
/* *_ 2db
**TestMethod.java D<=:9
*/ S&y(A0M
package NetFox; iw!kV
~_SoP
H"_ZqEg
public class TestMethod { :zXkQQD8`
v(+9&
1l$c*STK
public TestMethod() g5gq{KlU
{ ///xx/weblogic60b2_win.exe iXp*G52
try{ yQA6w%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); |/u&%w?W
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); czMThm
SiteFileFetch fileFetch = new SiteFileFetch(bean); ou;E@`h;x
fileFetch.start(); n>d@}hyv
} 1wX0x.4d
catch(Exception e){e.printStackTrace ();} "*E#4e[
o`hVI*D
iElE-g@Ws
} #7!P3j
?lg
w)A@
public static void main(String[] args) fiuF!<#;6
{ $q_e~+SXT
new TestMethod(); /%w9F
} '+6H=Qn
} oxN~(H)/ #
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