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)); =iW!Mq
} 'r~,~AI
for(int i=0;i<nEndPos.length-1;i++) IFcxyp
{ 8n+&tBq1
nEndPos = nStartPos[i+1]; L.ScC
} ]VtVw^ir
nEndPos[nEndPos.length-1] = nFileLength; mk(O..)2
} 4y\qJw)~U
} W/!M eTU&E
}Qyuy~-&^
~P8 6=Vw
//启动子线程 ^,*ED Yz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; `Fnl<C<
for(int i=0;i<nStartPos.length;i++) m5m}RWZ#
{ !~Gx@Ro
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :)o 4fOJ8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), O=~8+sa
nStartPos,nEndPos,i); ZKy)F-yX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s~ ||Vv!
fileSplitterFetch.start(); nr7#}pzo
} Yv<'QC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]L+YnZ?6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); PP)iw@9j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", RfH.WXi
nEndPos = " + nFileLength); ~QgyhJM_h=
// fileSplitterFetch[nPos.length-1].start(); TRP#b 7nC
q.0Evr:
!~Vo'ykwx'
//等待子线程结束 i[_(0P+Da
//int count = 0; yMaU`z
//是否结束while循环 5.m&93P
boolean breakWhile = false; }<R,)ZV^G
vT/e&8w
JjA3G`m=
while(!bStop) `EKmp|B_p_
{ ~puXZCatN
write_nPos(); b3R1L|@
Utility.sleep(500); I><B6pIR
breakWhile = true; G"k.sRKu
ha[c<e]uo[
qE B3Y54+
for(int i=0;i<nStartPos.length;i++) sZe$?k|
{ T8<pb^#
if(!fileSplitterFetch.bDownOver) .5L|(B=H
{ s?Lx\?T
breakWhile = false; >QyJRMY
break; 21NGsG
} paKur%2u
} ?tzJ7PJ~B
if(breakWhile) be?>C 5
break; ],`xd_=]=
7egE."
aa|u*afWQ
//count++; `HVS}}{a
//if(count>4) [|iWLPO1&k
// siteStop(); <PLQY
} =MR.*m{
o\/&05rp]
NOY`1i
System.err.println("文件下载结束！"); k=]#)A(#C
} -M]B;[^
catch(Exception e){e.printStackTrace ();} $Lj~ge3#
} >+,w2m@0
uqz HS>GM
?'_Ty`vT
//获得文件长度 Cws;6i*=@
public long getFileSize() s!k7Wwj
{ \r %y^G
int nFileLength = -1; G^r`)ND
try{ m(>MP/
URL url = new URL(siteInfoBean.getSSiteURL()); UY>[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^}SP,lg'
httpConnection.setRequestProperty("User-Agent","NetFox"); 4X-"yQ<U
CdBpz/
bG0 |+k3O
int responseCode=httpConnection.getResponseCode(); 87!D@Xn
if(responseCode>=400) ;X_bDiG$
{ yqH
processErrorCode(responseCode); .lsD+}
return -2; //-2 represent access is error m}UcF oaO
} T`?7z+2A
o*MiKgQ&
Xr:gm`[
String sHeader; 6ZO6O=KD
#ovausK[7
n?KhBJx 4
for(int i=1;;i++) q ~%'V
{ 4nsc`Hu
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p9>{X\eT:
//Utility.log(in.readLine()); ^fiJxU
sHeader=httpConnection.getHeaderFieldKey(i); GLO%>&
if(sHeader!=null) y+\kZIqX
{ ]z5kYU&
if(sHeader.equals("Content-Length")) 8H'ybfed
{ 3_bE12
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ?F6L,
break; ?"F9~vx&G
} ol0i^d*9F
} ^ps6\>=0cW
else @4t_cxmD
break; 7vo8lnQ{
} 4,,DA2^!
} %p48=|+
catch(IOException e){e.printStackTrace ();} H(hE;|q/
catch(Exception e){e.printStackTrace ();} HLe/|x\@<
4s s 4O
) $`}~
Utility.log(nFileLength); Y#,&Tu
s.X .SJ
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return nFileLength; '[Sm w'n6-
} |}7!'f\M
]'NL-8x">
DsB30
//保存下载信息（文件指针位置） 57fl<IM
private void write_nPos() YdZ9##IU3
{ #<LJns\t
try{ z''ejq
output = new DataOutputStream(new FileOutputStream(tmpFile)); 85x34nT
output.writeInt(nStartPos.length); C669:%
for(int i=0;i<nStartPos.length;i++) pG6?"*Fz;
{ KqN;a i,F
// output.writeLong(nPos); 216`rQ}z
output.writeLong(fileSplitterFetch.nStartPos); 2Z-[x9t
output.writeLong(fileSplitterFetch.nEndPos); "MvSF1
} nt]'>eX_}
output.close(); 7lx" X0w*m
} f,|g|&C
catch(IOException e){e.printStackTrace ();} z`qb>Y"xf3
catch(Exception e){e.printStackTrace ();} 0 <E2^
} eB&.keO
"Xg~1)%
;^TSla+t+
//读取保存的下载信息（文件指针位置） BTzBT%mP
private void read_nPos() 1{ H=The
{ b'ZzDYN
try{ s{Og3qUy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /F$E)qN7n
int nCount = input.readInt(); <~*[OwN
nStartPos = new long[nCount]; hj=qWGRgI
nEndPos = new long[nCount]; f\rE{%
for(int i=0;i<nStartPos.length;i++) ?n]adS{
{ k:&vW21E
nStartPos = input.readLong(); yq?\.~ax
nEndPos = input.readLong(); Q>q-6/|UX
} R XCjYzt
input.close(); ?I8r2M]
} A<] $[2qPj
catch(IOException e){e.printStackTrace ();} ?y]R /?
catch(Exception e){e.printStackTrace ();} i[?VF\Y(
} nC%<BatQ
]v/pMg#-
NQGa=kXeJ
private void processErrorCode(int nErrorCode) 4ClSl#X#i
{ C2aA])7D
System.err.println("Error Code : " + nErrorCode); **\?-*c=U
} TI}a$I*
dVPY07P
K.=5p/^a
//停止文件下载 =van<l4b#n
public void siteStop() y"Pd>61h
{ K5rra%a-7
bStop = true; P5H_iH
for(int i=0;i<nStartPos.length;i++) ]h#QA;
fileSplitterFetch.splitterStop(); T, +=ka$
&1f3e
NBXhcfF
} it-]-=mqb
} F [Lg,}
//负责部分文件的抓取 1 0zw}1x
**FileSplitterFetch.java K^6d_b&
*/ -%0pYB
package NetFox; gAh#H ?MM
{{Qbu}/@
jJaMkF;f
import java.io.*; bsm/y+R
import java.net.*; P:_bF>r ?
0K6My4d{
r7sA;Y\
public class FileSplitterFetch extends Thread { SA#01}&p
obGhO
kdWUz(
String sURL; //File URL k+%&dEE|vH
long nStartPos; //File Snippet Start Position ?(Ua+*b
long nEndPos; //File Snippet End Position 734t
int nThreadID; //Thread's ID U{KnjoS
boolean bDownOver = false; //Downing is over o*artMkG
boolean bStop = false; //Stop identical v k=|TE
FileAccessI fileAccessI = null; //File Access interface oeZUd}P
cRMyYdJ o
q`'"+`h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t`'jr=e,~
{ LXWI'nxV
this.sURL = sURL; qcouZO
this.nStartPos = nStart; Z)IF3{*
this.nEndPos = nEnd; o<J6KTLv
nThreadID = id; *Ojl@N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )7]yzc
} -Bl^TT
kxN O9w
C=|8C70[%N
public void run() 9=j)g
{ ML MetRP
while(nStartPos < nEndPos && !bStop) &XdTY +
{ qp)Wt6 k?
7R7+jL,
O) TS$
try{ O@ H.k<zn
URL url = new URL(sURL); $qr6LIKGw
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Qclq^|O0
httpConnection.setRequestProperty("User-Agent","NetFox"); 'e*w8h
String sProperty = "bytes="+nStartPos+"-"; 9gdK&/ulR
httpConnection.setRequestProperty("RANGE",sProperty); !V(r p80
Utility.log(sProperty); a$h^<D ^
;2\6U;
3^nH>f-Y
InputStream input = httpConnection.getInputStream(); /:Gy .
//logResponseHead(httpConnection); Zhv%mUj~
P$0c{B4I
b- e
byte[] b = new byte[1024]; iF Mf[qBg
int nRead; T&MhSJf#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "oNl!<ep
{ K6 >\4'q
nStartPos += fileAccessI.write(b,0,nRead); [>r0 (x&.
//if(nThreadID == 1) 09anQHa
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !H)-
} fqY'Uq$=
ZZZ9C#hK^9
)gSqO{Z
Utility.log("Thread " + nThreadID + " is over!"); T@i* F M
bDownOver = true; c?EvrtND
//nPos = fileAccessI.write (b,0,nRead); 8 /t';
} c AO:fb7
catch(Exception e){e.printStackTrace ();} }.&;NgZS
} T}=^D=
} {ri={p]l
A]5];c
Xpn\TD<_I
//打印回应的头信息 {4,],0bjx/
public void logResponseHead(HttpURLConnection con) #"rK1Z
{ 0"%dPKi
for(int i=1;;i++) fV5$[CL1
{ % g
String header=con.getHeaderFieldKey(i); eh<mJL%T
if(header!=null) [%^sl>,7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $.,B2}'
Utility.log(header+" : "+con.getHeaderField(header)); c+e?xXCEAz
else n`&D_AbQ
break; >8kXa.)84
} .4[3r[
} ^ex\S8j
bI|G %
&xN+a{&
public void splitterStop() $7DW-TA
{ $1|E(d1
bStop = true; fxPg"R!1i
} <6Gs0\JB
C'|9nK$%
lMGO4U[z
} reh{jMC
2I}pX9
;Go^)bN ;
/* U?:P7YWy
**FileAccess.java oH%[8!#
*//文件访问(定位，写) N=<`|I
package NetFox; i83~&Q=
import java.io.*; Ld}?daPj
X'PZCg W
>bf.T7wy
public class FileAccessI implements Serializable{ f|q/2}Bqb
<z,)4z++
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e6j1Fa9
RandomAccessFile oSavedFile; y'!OA+ob
long nPos; $YEm(:v$
T3zovnR
?<!qF:r:
public FileAccessI() throws IOException 3Xu|hkK\e
{ Cj8&wz}ez
this("",0); js81@WX!c
} kx;X:I(5&P
*{w0=J[15
JK =A=
public FileAccessI(String sName,long nPos) throws IOException '37 {$VHw
{ c}qpmWF
oSavedFile = new RandomAccessFile(sName,"rw"); Jh EC
this.nPos = nPos; r/!,((Z\
oSavedFile.seek(nPos); xOe1v9<
} Z?'CS|ud
]LC4rS
n;Oe-+oSC
public synchronized int write(byte[] b,int nStart,int nLen) }MRgNr'k
{ )_jboaNzwI
int n = -1; larv6ncV
try{ _Rii19k
oSavedFile.write(b,nStart,nLen); ~{Iw[,MJ
n = nLen; a|u#w~
} o7!A(Eu
catch(IOException e) ;]-08lzO<4
{ XZ |L D#
e.printStackTrace (); o&1mX
} })-V,\
g9pKoi|\E
<\^o
return n; crIF5^3Yby
} ta)gOc)r R
5?>4I"ne
L}*o8l`
} 71nZi`AR
f 3H uT=n
oDA'$]UL
/* ^@V*:n^
**SiteInfoBean.java ,zoHmV1Wd+
*/ 7#E/Q~]'6
package NetFox; Z{^!z
s9wzN6re
-t4:%-wv
public class SiteInfoBean { MF"*xr v
=T[P
daKZ*B|
private String sSiteURL; //Site's URL gtuSJ+up
private String sFilePath; //Saved File's Path 8UjIC4'
private String sFileName; //Saved File's Name CB#2XS>V
private int nSplitter; //Count of Splited Downloading File ^&YtZjV
K:U=Y$x
R@3HlGuRKw
public SiteInfoBean() Y5GN7.
{//nSplitter的缺省值为5 @o0HDS
//default value of nSplitter is 5 XE2Un1i}j1
this("","","",5); 0cHcBxdF
} MM32\}Y6
:5~Dca_iU4
1/9*c *w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,h^6y
{ QIkFX.^
sSiteURL= sURL; gV@xu)l
sFilePath = sPath; aftt^h
sFileName = sName; \;0pjxq=
this.nSplitter = nSpiltter; F\JS?zt2
E^rBs2;9
bKS/T^UQ
} EcHZmf
rd->@s|4mT
VjWJx^ZL#
public String getSSiteURL() i<Ms2^
{ !hQ-i3?qm
return sSiteURL; GhfhR^P
} wetu.aMp
gaXo)oS
i`@cVYsL
public void setSSiteURL(String value) Lmjd,t
{ #eKKH]J/
sSiteURL = value; a^&"gGg
} }` 3-
\5}PF+)|
;b [>{Q;
public String getSFilePath() =r/K#hOR\J
{ I '0[
return sFilePath; *x8~}/[T(F
} ZiR}S
G%~Vb
|gA@$1+}
public void setSFilePath(String value) 9q?knMt
{ my sXgS&S
sFilePath = value; 8x1!15Wiz
} &pI\VIx ?
9mvy+XD
jW#dUKS(
public String getSFileName() i%133in
{ M{p6&eg
return sFileName; zk$h71<{.
} {($mLfC4
2+pw%#fe
)b nGZ8h99
public void setSFileName(String value) \Nik`v*Pd
{ eM$a~4!d
sFileName = value; %. ((4 6)
} nycJZ}f:wP
,'c%S|]U7
%rs2{Q2k
public int getNSplitter() [5xm>Y&}
{ 53uptQ{
return nSplitter; 9*iVv)jd
} 1N _"Mm{
[uqr
4Ty?>'*|
public void setNSplitter(int nCount) xy>$^/[$
{ /w dvm4
nSplitter = nCount; &S.p%Qe"
} ;,Vdj[W$>
} # d"M(nt
0 F8xS8vK+
o7we'1(O
/* <*iFVjSI(
**Utility.java hlyh8=Z6o
*/ ~jKIuO/
package NetFox; bL<H$DB6
d.ywH;
@~{TL
public class Utility { f4<~_ZGr
7]u_
,FYA*}[
public Utility() Q +hOW-
{ b^[>\s'
t`&mszd~T
s7E %Et
} si%V63^lN
`&a8Wv
//线程睡眠 aU +uPP
public static void sleep(int nSecond) \zVp8MMf
{ xg%{p``
try{ B7A.~'=
Thread.sleep(nSecond); `o_i+?E
} ZyU/ .Uk
catch(Exception e) 0*^f EoV
{ x2~fc
e.printStackTrace (); 5Q}HLjG8Z
} !bK;/)
} #/(L.5d[
.h w(;
//日志 QncjSaEE
public static void log(String sMsg) S% ptG$Z
{ %xx;C{g;a
System.err.println(sMsg); vRmzjd~
} !N:w?zsp
/jaO\t'q
?~^p:T
public static void log(int sMsg) " d~M\Az
{ r+]a
System.err.println(sMsg); `T2DGv
} <6N3()A)%1
} Q\~#cLJ/
ieEtC,U
ENYc.$r
/* w0>5#jq#r
**TestMethod.java f:t5`c.
*/ ,+Ya'4x
package NetFox; ;rh=63g
i+-=I+L3
qk&BCkPT
public class TestMethod { 6jal5<H
{dl@#Tu
EA:_PBZ
public TestMethod() s0Y7`uD^
{ ///xx/weblogic60b2_win.exe !vr A\d
try{ W70BRXe04D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); odeO(zuU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~8Ef`zL
SiteFileFetch fileFetch = new SiteFileFetch(bean); @$ )C pg
fileFetch.start(); E&vCzQ
} CZv^,O(M?2
catch(Exception e){e.printStackTrace ();} mh_GYzd
\bSakh71
)A;jBfr
} o5z&sRZ
fb]=MoiJ
Q!fk|D+j
public static void main(String[] args) HBa6Y&)<
{ n 8|
new TestMethod(); %eu_Pr6X
} H~<wAer,Op
} e $5s],,n
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