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)); =m2_:&@0x
} aKriO
for(int i=0;i<nEndPos.length-1;i++) ),p0V
{ Z|n|gxe
nEndPos = nStartPos[i+1]; =Q(J!f
} (uvQ/!
nEndPos[nEndPos.length-1] = nFileLength; U_*,XLU
} @\?ubF
} *ai~!TR
?4R%z([X7
7(+4^
//启动子线程 e&z@yy$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `#ruZM066
for(int i=0;i<nStartPos.length;i++) ?A|JKOst]
{ t,fec>.
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v-z%3x.f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 66pjWS {X
nStartPos,nEndPos,i); 1;(h0j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~6i'V?>
fileSplitterFetch.start(); Gf"TI:xa
} / rc[HbNg.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [L+*pW+$\.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fG'~@'P~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", VG 5*17nf5
nEndPos = " + nFileLength); VBL4cU8D
// fileSplitterFetch[nPos.length-1].start(); OWewV@VXR
Wz'!stcp
hEB5=~A_
//等待子线程结束 G*N[tw
//int count = 0; 5bt>MoKxv
//是否结束while循环 ~wDXjn"U&
boolean breakWhile = false; pRun5 )7
,kJ7c;:i
v](Y n)#
while(!bStop) o9e8Oj&
{ MG vz-E1e
write_nPos(); Dq<la+VlO
Utility.sleep(500); J| N 6r
breakWhile = true; 4 -tC=>>wc
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for(int i=0;i<nStartPos.length;i++) Fy{yg]O"
{ d2UidDU5qa
if(!fileSplitterFetch.bDownOver) N-upNuv
{ c7r(&h
breakWhile = false; YAc:QVT87
break; )oCL![^pXe
} HMF2sc$N
} fc3nQp7
if(breakWhile) }%Mdf6LS64
break; <u\Hy0g
xJ$uoy3+
,A{Bx`o?
//count++; A8&@Vxdz
//if(count>4) 8S#$'2sT
// siteStop(); }eVDe(7_
} 8s6[-F5
B9NUafK=
"a[;{s{{.
System.err.println("文件下载结束！"); !tTv$L>
} r[!~~yu/o
catch(Exception e){e.printStackTrace ();} }9\_s*
} \]<R`YMV
@ 3=pFYW)
( 3B1X
//获得文件长度 4JK6<Pk
public long getFileSize() 29J|eBvxx
{ :<P4=P P
int nFileLength = -1; <}WSYK,zUY
try{ 6HCg<_j]
URL url = new URL(siteInfoBean.getSSiteURL()); w0g@ <( 3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); # QwX|x{
httpConnection.setRequestProperty("User-Agent","NetFox"); V5lUh#@TN&
6 EqN>.
dQIF'==6
int responseCode=httpConnection.getResponseCode(); 7#C$}1XJ1
if(responseCode>=400) ;t+p2i
{ T@ESMPeU:X
processErrorCode(responseCode); 5Yv*f:
return -2; //-2 represent access is error AVjRhe
} R_G2C@y*
.eIs$
b<y*:(:
String sHeader; 7=N%$]DKZ
o`n8Fk}i
l\ dPfJ
for(int i=1;;i++) 9!=4}:+
{ a&G{3#l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); :.AC%'S
//Utility.log(in.readLine()); _:\rB
sHeader=httpConnection.getHeaderFieldKey(i); CfW#Wk:8J
if(sHeader!=null) !X7z y9
{ G)~>d/
if(sHeader.equals("Content-Length")) SHYekX
{ D-@6 hWh~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ]7<$1ta
break; CL2zZk{u_
} di_UJ~
} fZf>>mu@r'
else LNJKf6:
break; huv|l6
} a"P & 9c
} e/Z{{FP%6
catch(IOException e){e.printStackTrace ();} 6?}|@y^fb
catch(Exception e){e.printStackTrace ();} ,2!7iX
mIf)=RW
BsXF'x<U*
Utility.log(nFileLength); i +@avoW
4}D&=0IZ
H%n/;DW
return nFileLength; j6^.Q/{^
} l1zPL3"u_^
*H/)S5
!Yo2P"
//保存下载信息（文件指针位置） _K?v^oM#
private void write_nPos() vrmMEWPV
{ JUw|nUnl?
try{ NUiv"tAY
output = new DataOutputStream(new FileOutputStream(tmpFile)); r^.9 |YM5
output.writeInt(nStartPos.length); 8ZV!ld
for(int i=0;i<nStartPos.length;i++) K @&c
{ Q-h< av9
// output.writeLong(nPos); ~uY5~Qs9G
output.writeLong(fileSplitterFetch.nStartPos); U!+O+(
output.writeLong(fileSplitterFetch.nEndPos); hFoeVM[h
} 0o7o;eN
output.close(); -U>)B
} [i~@X2:Al
catch(IOException e){e.printStackTrace ();} Z-t qSw8n
catch(Exception e){e.printStackTrace ();} pDP* 3
} 6$PQ$
OkQ< Sc
?_{{iil
//读取保存的下载信息（文件指针位置） TQt[he$O
private void read_nPos() 9r\p4_V
{ zfUj%N
try{ n=rmf*,?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l{rHXST|
int nCount = input.readInt(); g NE"z
nStartPos = new long[nCount]; Ld:-S,2
nEndPos = new long[nCount]; a$uDoi
for(int i=0;i<nStartPos.length;i++) 6G4~-_
{ [D|Uwq
nStartPos = input.readLong(); M&Q&be84
nEndPos = input.readLong(); uAYDX<Ja9
} 0Q>
input.close(); FFwu$S6e
} HRahBTd(z
catch(IOException e){e.printStackTrace ();} BpFXe7
catch(Exception e){e.printStackTrace ();} Y"5FK
} @pvQci
A5fzyG
Kk.\P|k2
private void processErrorCode(int nErrorCode) 'yOx&~H]
{ #( 4)ps.
System.err.println("Error Code : " + nErrorCode); C]ho7qC
} qzY:>>d'
3 P\4K
'u PI~l`g
//停止文件下载 JvT#Fxjk
public void siteStop() @B+8' b$9
{ y\6C9%.
bStop = true; h{]0 H'g
for(int i=0;i<nStartPos.length;i++) qoQ,3&<
fileSplitterFetch.splitterStop(); wMm+E "}W
6a]Qg99\
Nsy>qa7
} h/aG."U
} G^P9_Sw]d3
//负责部分文件的抓取 , Z1 &MuV
**FileSplitterFetch.java rIv#YqT
*/ IH=%%AS
package NetFox; Ka{QjW!%d<
suX^"Io%!
jxw8jo06:
import java.io.*; *W}nw$tnBX
import java.net.*; bA"*^"^
7'.6/U
s?sr0HZ
public class FileSplitterFetch extends Thread { ayf;'1
q|B.@Ng.
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String sURL; //File URL _}H`(d%N
long nStartPos; //File Snippet Start Position <aMihT)dd
long nEndPos; //File Snippet End Position 's8LrO(=
int nThreadID; //Thread's ID d8jP@>
boolean bDownOver = false; //Downing is over =6'D/| 3
boolean bStop = false; //Stop identical $xcU*?=K
FileAccessI fileAccessI = null; //File Access interface O[}2
ac43d`wpK
yW(A0
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @`sZV8
{ z[+pN:47
this.sURL = sURL; *q1sM#;5
this.nStartPos = nStart; KH$o X\v
this.nEndPos = nEnd; >va9*pdJ
nThreadID = id; OYfP!,+bn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ui*CA^ Y
} "y .(E7 6
#=fd8}9
/h!iLun7I
public void run() v Dph}Z
{ #Nv0d|0\
while(nStartPos < nEndPos && !bStop) G;msq=9|
{ 5)K?:7
=-uk7uZM
7:)$oH
try{ #0M,g
URL url = new URL(sURL); XR)I,@i`'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KDAZG+u+
httpConnection.setRequestProperty("User-Agent","NetFox"); JR/^Go$^
String sProperty = "bytes="+nStartPos+"-"; SI l<\
httpConnection.setRequestProperty("RANGE",sProperty); _@]@&^K$E
Utility.log(sProperty); K@=_&A!
-QydUr/(o
\xtmd[7lb<
InputStream input = httpConnection.getInputStream(); j98>Jr\
//logResponseHead(httpConnection); u $T'#p1
<Y#EiC.
/I#SP/M&l
byte[] b = new byte[1024]; / ='/R7~
int nRead; z:tu_5w!,
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [~rBnzb
{ j0K}nS\ P
nStartPos += fileAccessI.write(b,0,nRead); ~Ywto
//if(nThreadID == 1) dLu3C-.(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1j^FNg~
} S|v-lJ/I
ki_Py5
852Bh'u_
Utility.log("Thread " + nThreadID + " is over!"); h3L{zOff
bDownOver = true; kF*^" Cn
//nPos = fileAccessI.write (b,0,nRead); Kd,7x'h`E
} BBm;QOBU
catch(Exception e){e.printStackTrace ();} A?OaP
} GfT`>M?QGK
} 6t6#<ts
!Zf)N_k
,ffH:3F
//打印回应的头信息 KbF,jm5
public void logResponseHead(HttpURLConnection con) d\aU rsPn
{ U_c9T>=
for(int i=1;;i++) ur`:wR] 2?
{ 2f@gR9T
String header=con.getHeaderFieldKey(i); JS1''^G&.
if(header!=null) [VwoZX:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (%EhkTb
Utility.log(header+" : "+con.getHeaderField(header)); IE9A _u*
else xk5Z&z
break; 7L&=z$U@m
} G8oOFBQD
} l<RztzUw
(f|3(u'e?
pVm'XP
public void splitterStop() GKKf#r74
{ fg1["{\
bStop = true; snyg
} vSy#[9}
B?J#NFUb
U_c.Z{lC4
} ]`Y;4XR
u($y<Q)=
K%A:W
/* hK&/A+*
**FileAccess.java <$'OSN`!
*//文件访问(定位，写) GoNX\^A
package NetFox; ,0=:06l
import java.io.*; "+V.Yue`R
pTlNJ!U>
J@c)SK%2h
public class FileAccessI implements Serializable{ k:0HsN!F9
\{[Gdj`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `8%2F}x}qD
RandomAccessFile oSavedFile; ;u0MY
long nPos; $k|k5cP8x
}l>0m
&8 ~+^P1w
public FileAccessI() throws IOException hqVFb.6[
{ H`;q@
this("",0); Fh4kd>1D
} a$SGFA}V
14p <0BG
fWywegh
public FileAccessI(String sName,long nPos) throws IOException 0x\bDWZ_
{ TPrqb
oSavedFile = new RandomAccessFile(sName,"rw"); Gt^Fj&^
this.nPos = nPos; OXuBtW*,z+
oSavedFile.seek(nPos); q8{)27f,
} C-abc+/
;X ]+r$_
dk9'C
public synchronized int write(byte[] b,int nStart,int nLen) |A#pG^
{ @e_ bG@
int n = -1; j\D_Z{m2
try{ |BGQ|7DyG
oSavedFile.write(b,nStart,nLen); hX~d1.]Y
n = nLen; y pv~F
} OFTyN^([@
catch(IOException e) }Zue?!KQ
{ I|*w?i*
e.printStackTrace (); emo@&6*
} }0Qex=vkO
CD'.bFO^+T
?[}r& f
return n; ~e5hfZv|w
} ew#t4~hh
WCc,RI0
%># VhK
} %(IkUD
9"3 7va
K"O+`2$
/* OsMU>v }m
**SiteInfoBean.java \s8j*
*/ |gW>D=rkj
package NetFox; FabzP_<b
+pcpb)VL
/d*0+m8
public class SiteInfoBean { RG9YA&1ce
)DS|mM)
r wtU@xsD
private String sSiteURL; //Site's URL )A}u)PH4O
private String sFilePath; //Saved File's Path dC$z q~q
private String sFileName; //Saved File's Name 6px(]QU
private int nSplitter; //Count of Splited Downloading File -s5j^U{h|
[eebIJs
[%M=nJ{8
public SiteInfoBean() Wm{Lg0Nr
{//nSplitter的缺省值为5 :nZVP_d+
//default value of nSplitter is 5 ?8AchbK;N
this("","","",5); @7Oqp-
} 7cTDbc!E-
!=7(3<?
]_6w(>A@3#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gJEm
{ J3OxM--8"
sSiteURL= sURL; 1&JPyW
sFilePath = sPath; eM";P/XaX
sFileName = sName; ToWiXH)4
this.nSplitter = nSpiltter; @kCFc}
5hN`}Ve
RjC3wO::
} +>b~nK>M
DlHt#Ob7
[ZC{eg+D
public String getSSiteURL() v803@9@
{ WZ\bm$
return sSiteURL; A dNQS
} LO8`qq*rq
SJg4P4|
V(hM@ztN
public void setSSiteURL(String value) F7!g+LPc<
{ ,Jm2|WKH
sSiteURL = value; jlvh'y`
} ' U]\]Wp
x3j)'`=15
J:<mq5[
public String getSFilePath() .E H&GX
{ ws1io.
return sFilePath; l`S2bb6uMR
} #aX+?z\4
)k)HQcfjD
r%`g` It
public void setSFilePath(String value) 1>I4=mj
{ ]_!5g3VQh
sFilePath = value; >|{n";n&
} U($bR|%D
LH7m >/LJr
F|+Qi BO
public String getSFileName() . V5Pr}"y
{ <'n'>@
return sFileName; )ry7a .39b
} US5]@!
"DN0|%`M/
SlU?,)J}
public void setSFileName(String value) d 8YP<"V&
{ MI^@p`s
sFileName = value; tB S+?N
} BlwAD
Q=YIAGK
*0vq+C
public int getNSplitter() O;zq(/,-l
{ I5#KLZVg
return nSplitter; t zn1|
} cQg:yoF
4= 7#=F1
\9 ,a"g
public void setNSplitter(int nCount) !3O8B0K)v
{ O52B
nSplitter = nCount; 73Zx`00
} JWZG)I]r
} 8 5 L<
GkwdBy+
/!7
/* bsuGZ
**Utility.java z):LF<
*/ b/[$bZD5o
package NetFox; voX4A pl
O0Z!*Hy
^/6LVB*
public class Utility { 1zNh& "
vIq>QXb;d
<M){rce
public Utility() VQ}N&H)`
{ }?eO.l{
p{@jM
FIMM\W
} u[:-^H
rY?]pMp
//线程睡眠 a/wg%cWG_
public static void sleep(int nSecond) s9#WkDR
{ PHAM(iC&D
try{ Dj9v9
Thread.sleep(nSecond); D02'P{
} YCPU84f
catch(Exception e) hwx1fpo4
{ aB_~Vh
e.printStackTrace (); 2ezk<R5q+
} nYsB^Nr6
} /Fr*k5I
Ez1-Nx
//日志 ylGT9G19
public static void log(String sMsg) ?^3Y+)}
{ 14~#k%zO(
System.err.println(sMsg); FhP$R}F
} ;B^ 9sr
nyoLrTs{
'048Qykt;
public static void log(int sMsg) } yb"/jp
{ tZXq<k9
System.err.println(sMsg); (Sv=R(_s
} ;W 3#q:
} H\%^n<]#
"g5<jp
ge#0Q L0K
/* 5)c B\N1u
**TestMethod.java Lo<WK
*/ ?]%ZJd
package NetFox; i,h)VCc
T^ )\
m$.7) 24
public class TestMethod { SuR+Vv
d53Eu`QW?
w#d7
public TestMethod() !U7}?i&H
{ ///xx/weblogic60b2_win.exe mI,a2wqi
try{ rff_=(?i
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :Z[|B(U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); h wi!C}
SiteFileFetch fileFetch = new SiteFileFetch(bean); Gh5 3Pne
fileFetch.start(); 1Y:JGon
} ?vBMx _0
catch(Exception e){e.printStackTrace ();} r9Vt}]$aG
[-0=ZKH?
RRb>]oD
} H73 r3BH
|jI|},I
gJH^f3
public static void main(String[] args) 79z/(T+
{ t`- [
new TestMethod(); 'WNq/z"X
} tjLG$M1z`
} m0i,Zw{eM
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