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)); `DgaO-Dg3
} #Acon7Rp
for(int i=0;i<nEndPos.length-1;i++) u#a%(
{ A0cM(w{7_
nEndPos = nStartPos[i+1]; 38V $<w
} ^3Z7dIUww
nEndPos[nEndPos.length-1] = nFileLength; $ 7UDz
} l?[{?Luq
} f pv= P
%+AS0 JhB
T7>48eH
//启动子线程 ewb*?In
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ntrY =Y
for(int i=0;i<nStartPos.length;i++) 8Zcol$XS'
{ n~1tm
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2x7(}+eD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Nd]0ta
nStartPos,nEndPos,i); &ui:DZAxj|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); );Tx5Z}
fileSplitterFetch.start(); [n!$D(|"!V
} 9nT?|n]>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kJ%{ [1fr
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); QRsqPh&-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;Ri 3#*a=
nEndPos = " + nFileLength); ~v.jZ/h
// fileSplitterFetch[nPos.length-1].start(); RpHpMtvNo/
<MPeh&_3#
f|- m ^/y
//等待子线程结束 ,|e}Y [
//int count = 0; j4E H2v
//是否结束while循环 U>/<6Wd
boolean breakWhile = false; IY];Ss&i
bin6i2b
]*bAF^8i
while(!bStop) GwgFi@itN
{ k-{yu8*';
write_nPos(); #=X)Jx~
Utility.sleep(500); ShC_hi
breakWhile = true; #^5a\XJb
:~\LOKf
n?y'c^
for(int i=0;i<nStartPos.length;i++) ^c/mj9M#C
{ F{TC#J}I%'
if(!fileSplitterFetch.bDownOver) y<O@rD8iA
{ 8B}'\e4i
breakWhile = false; *<B)Z
break; yr FZ~r@-
} xCR; K]!
} ]XmQ]Yit
if(breakWhile) VYL@RL'
break; 6P0y-%[Gk
cDfx)sL
2~vo+ng
//count++; <\>+~p,
//if(count>4) nVz5V%a!\q
// siteStop(); \9046An
} Ya~ "R#Uy
x^zdTMNhw
I)[`ZVAXR
System.err.println("文件下载结束！"); W\HLal
} ;l$9gD>R
catch(Exception e){e.printStackTrace ();} "4'kb
} [<_"`$sm=
MB1sQReOO
}16&1@8
//获得文件长度 l*$WX=h6n
public long getFileSize() \eEds:Hg
{ WLE%d]'%M
int nFileLength = -1; :9(3h"
try{ `2>XH:+7F
URL url = new URL(siteInfoBean.getSSiteURL()); ?lF mXZy`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \|v`l{
httpConnection.setRequestProperty("User-Agent","NetFox"); V@B7P{gH
\s,Iz[0Vfz
7@FDBjq
int responseCode=httpConnection.getResponseCode(); 3}08RU7[!
if(responseCode>=400) )\8URc|J
{ yPSVwe|g
processErrorCode(responseCode); 66/Z\H^d
return -2; //-2 represent access is error E^7C _JP
} DP|TIt,Rl
"]v uD
,oBlJvm
String sHeader; :aHcPc:
DLU[<!C
VK9Q?nu
for(int i=1;;i++) JRD8Lz]Q3
{ Ud$Q0m&
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ])eOa%
//Utility.log(in.readLine()); DG3[^B
sHeader=httpConnection.getHeaderFieldKey(i); D`en%Lf!m
if(sHeader!=null) |pBMrN+is
{ +-U@0&Y3M
if(sHeader.equals("Content-Length")) pQqbZ3]
{ a|U}Ammr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); I=U+GY:
break; ]y.Rg{iv
} VF\{ra;
} l`DtiJ?$$0
else 4 ^4d9?c
break; ]Qd{ '}+
} IeZ&7u
} UIQQ\,3
catch(IOException e){e.printStackTrace ();} vuXS/ d
catch(Exception e){e.printStackTrace ();} HF]EU!OT
j]>=1Rd0b(
4ffU;6~l'
Utility.log(nFileLength); ~xw5\Y^
yE}BfU {.
f?Z|>3.2
return nFileLength; `N$!s7M
} Tj&'KF8?L
l"kxr96
c!mG1lwD.
//保存下载信息（文件指针位置） "@4ghot t
private void write_nPos() &2Q*1YXj
{ b"Zq0M0l
try{ {H+?z<BF<
output = new DataOutputStream(new FileOutputStream(tmpFile)); J,RDTXqn
output.writeInt(nStartPos.length); !I~C0u
for(int i=0;i<nStartPos.length;i++) #VO.%H}i
{ Ey'J]KVW
// output.writeLong(nPos); Vd21,~^>g
output.writeLong(fileSplitterFetch.nStartPos); un6cD$cHr
output.writeLong(fileSplitterFetch.nEndPos); `%oIRuYG]j
} =rEA:Q`~w
output.close(); mGO>""<:
} `YU=~xQ
catch(IOException e){e.printStackTrace ();} xHHV=M2l(s
catch(Exception e){e.printStackTrace ();} &-=K:;x
} "NKf0F
{8 N=WZ
x)3~il5
//读取保存的下载信息（文件指针位置） Vg{Zv4+t
private void read_nPos() p!}ZdX[u
{ mW~P!7]
try{ U_l7CCK +
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pr$~8e=c
int nCount = input.readInt(); D;jK/2
nStartPos = new long[nCount]; #MglHQO+
nEndPos = new long[nCount]; Ge^Qar
for(int i=0;i<nStartPos.length;i++) @ ICbKg:
{ f|#8qiUS
nStartPos = input.readLong(); Fom>'g*
nEndPos = input.readLong(); Z["BgEJ
} I(n }<)eF
input.close(); p-,Iio+
} S.W^7Ap
catch(IOException e){e.printStackTrace ();} mL$f[
catch(Exception e){e.printStackTrace ();} v77fQ0w3
} S7CV w,2
'l|R5
ljVIE/iq
private void processErrorCode(int nErrorCode) =e{.yggE
{ r1;e 0\?`
System.err.println("Error Code : " + nErrorCode); L<=)@7
} (UGol[f<
'B`#:tX^N
=*O=E@]
//停止文件下载 f TO+ZTRqf
public void siteStop() Tm_8<$ 7
{ ;%Q&hwj
bStop = true; bK4&=#Zh
for(int i=0;i<nStartPos.length;i++) x,\!DLq:p
fileSplitterFetch.splitterStop(); R*bmu
4sIXO
NI.`mc6Xd
} {fU?idY)c
} *T1~)z}j<
//负责部分文件的抓取 y(}Eko4u5
**FileSplitterFetch.java \2>?6zs
*/ nvt$F%+
package NetFox; h>klTPM>
I+",b4
VoM6
import java.io.*; "r..
import java.net.*; OJpj}R
LG&5VxT=,<
|` "?
public class FileSplitterFetch extends Thread { 2m"_z
'MN1A;IJ
+/y]h0aa
String sURL; //File URL A=X-;N#
long nStartPos; //File Snippet Start Position \[ M_\&GC
long nEndPos; //File Snippet End Position $;`I,k$0>~
int nThreadID; //Thread's ID [;^,CD|P
boolean bDownOver = false; //Downing is over ^N-'xy
boolean bStop = false; //Stop identical #\ #3r
FileAccessI fileAccessI = null; //File Access interface 7"cv|6y|
,r`UBQ}?
/2XW
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException o @KW/RN"
{ .6m_>Y6
this.sURL = sURL; f{ ^:3"i
this.nStartPos = nStart; iSiDSeW8
this.nEndPos = nEnd; %w5[*V
nThreadID = id; J +q|$K6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Qqq <e
} V`bs&5#Sx
si(cOCj/
($>XIb9f
public void run() [s}/nu~U
{ 4pPI'd&/7
while(nStartPos < nEndPos && !bStop) e_rzA
{ S4bBafj[I
]JMl|e
Qn|+eLY
try{ Jhy(x1%
URL url = new URL(sURL); OipqoI2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p3yU:q#A
httpConnection.setRequestProperty("User-Agent","NetFox"); 9$RIH\*
String sProperty = "bytes="+nStartPos+"-"; $iPP|Rw
httpConnection.setRequestProperty("RANGE",sProperty); +pp9d-n
Utility.log(sProperty); CVQB"L
_kN*e:t
;GOz>pg
InputStream input = httpConnection.getInputStream(); NY!jwb@%
//logResponseHead(httpConnection); fu]N""~
hO( RZ'{
H~o <AmE0!
byte[] b = new byte[1024]; g_z/{1$
int nRead; t&}6;z 3
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y LM"+.?pL
{ SaO3zz@L
nStartPos += fileAccessI.write(b,0,nRead); {rXs:N@
//if(nThreadID == 1) 61@EDIYPc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); o8ppMM8_R[
} XUSvhr$|
!#}7{
O3qM1-k}S
Utility.log("Thread " + nThreadID + " is over!"); Phs-(3
bDownOver = true; dR+1aY;
//nPos = fileAccessI.write (b,0,nRead); 4!%F\c46
} fdv`7u+}a
catch(Exception e){e.printStackTrace ();} BsLG^f
} f/y`
} DWm SC}{.
n:4uA`Vg
Z cpmquf8L
//打印回应的头信息 >EP(~G3u
public void logResponseHead(HttpURLConnection con) 4["&O=:d
{ Tlodn7%",
for(int i=1;;i++) HOZRYIQB
{ !'0S0a8
String header=con.getHeaderFieldKey(i); >NM\TLET~
if(header!=null) Bs!4H2@{(]
//responseHeaders.put(header,httpConnection.getHeaderField(header)); FxRXPt FK
Utility.log(header+" : "+con.getHeaderField(header)); "A[ b rG
else |d}MxS`^
break; 2UadV_s+s
} _MfD
} k \qiF|B)Z
e@n!x}t8
fly,-$K>LO
public void splitterStop() 2R.2D'4)`
{ UVEz;<5@\
bStop = true; J4aBPq`
} xf,5R9g/
W?XizTW
1*Ar{:+ua
} `G$1n#&
BfmsMW
k6**u
/* )=^w3y
**FileAccess.java `<fh+*
*//文件访问(定位，写) 9|WV~
package NetFox; ga0'zo9K
import java.io.*; Ph,-sR
PQ U]l"A
f3tv3>p
public class FileAccessI implements Serializable{ ~<9{#uM
c&'JmKV>&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %fjuG
RandomAccessFile oSavedFile; z#Nl@NO&
long nPos; Fn|gVR
]v29 Rx
uTvv(f
public FileAccessI() throws IOException 'Kbl3fUF
{ QIU,!w-3X
this("",0); Is.WZYa
} 0l\y.
%NARyz
Qt+:4{He
public FileAccessI(String sName,long nPos) throws IOException z/]q)`G
{ 0$P/jt
oSavedFile = new RandomAccessFile(sName,"rw"); buMqF-j
this.nPos = nPos; :k,Q,B.I
oSavedFile.seek(nPos); .tXtcf/
} {}Ejt:rKN
t?)pl2!A
[=%YV# O
public synchronized int write(byte[] b,int nStart,int nLen) C>QIrZu
{ Oejq@iM"(
int n = -1; , c;eN
try{ \nvAa_,
oSavedFile.write(b,nStart,nLen); {]}s#vvy
n = nLen; @QEqB_W
} 0pgY1i7
catch(IOException e) e}{U7xQm1
{ $t=O:
e.printStackTrace (); 3f76kl(&
} 6][1<}8
*nTU#U
-9Ws=r0R
return n; &h~aChJ
} MXvXVhCU
;%!m<S|%k
0E/:|k
} _|{aC1Y!V
!?FK We
1s7^uA$}6
/* 2k -+^}r
**SiteInfoBean.java C!x/ ^gw
*/ >'=MH2;
package NetFox; %{5n1w
HgRwiIt
gn1(4 o
public class SiteInfoBean { l=P'B @,
eC`pnE
ljJ>;g+
private String sSiteURL; //Site's URL z3?\:Yz
private String sFilePath; //Saved File's Path `NNf&y)y
private String sFileName; //Saved File's Name 6f%DpJ:$U
private int nSplitter; //Count of Splited Downloading File RMXzU
yJJ4~j){l
EeQ5vqU
public SiteInfoBean() yJ2B3i@T4
{//nSplitter的缺省值为5 4&X*pL2;
//default value of nSplitter is 5 dZ(|uC!?
this("","","",5); 4dh+
} Ca>&
vK'?:}~
LXfCmc9|Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 0tz:Wd*<
{ K%g;NW
sSiteURL= sURL; 5z/Er".P
sFilePath = sPath; )mN9(Ob!
sFileName = sName; \E4B&!m
this.nSplitter = nSpiltter; ~Gv#iRi>
\NL+}cL/
:14i?4Fd
} L2z2}U=<
-V<t-}h.
"4xfrlOc
public String getSSiteURL() '/%zi,0
{ UVuDQ
return sSiteURL; )mcEQ-!b
} fys
]F*3"y?)2
^HA %q8| n
public void setSSiteURL(String value) X]*QUV]i
{ VM=+afY5M
sSiteURL = value; oR#:NtX@
} '\DSTr:N
HeN~c<NuB
x^=M6;:
public String getSFilePath() &<x@1,
{ Ukphd$3J=
return sFilePath; qN| fEO>
} VHUW]8We
30cd| S?
&XLD S=j
public void setSFilePath(String value) ?w&SW{ I
{ /X8<C=}
sFilePath = value; \}]iS C.2
} |QZ58)>
' P"g\;Ij
[IBQvL
public String getSFileName() yubSj*
{ %:C ]7gQ
return sFileName; r64u31.)
} ! T9]/H?
Yxd X#3
C*70;:b
public void setSFileName(String value) dKhA$f~
{ C*6S@4k
sFileName = value; IO$z%r7
} # '|'r+
E8}+k o
!b|'Vp^U
public int getNSplitter() D^F{uDlb
{ s4= "kT]
return nSplitter; 0Fr1Ku!
} _!V%fw
^U7OMl4Usq
VV_l$E$
public void setNSplitter(int nCount) LJzH"K[Gg6
{ R!x: C!{
nSplitter = nCount; 76fIC
} Pt< s* (
} JcO08n
B/uniR^x
wFn[9_`*
/* l95<QI
**Utility.java ><?BqRm+
*/ `m~syKz4A
package NetFox; V`hu,Y;%
e_3CSx8Cc
D$eB ,~
public class Utility { jdqj=Yc
ctmQWrk|B
u62)QJE
public Utility() }odV_WT
{ |01?w|
bMoAD.}
d}I(`%%)
} (zo^Nn9VJ
b B
//线程睡眠 M~T.n)x2
public static void sleep(int nSecond) $A\m>*@
{ ekSY~z=/u
try{ i^z`"3#LE
Thread.sleep(nSecond); P1zK2sL_
} !E\[SjY@J
catch(Exception e) }qPhx6nP
{ Zy"=y+e!E;
e.printStackTrace (); tB(4Eq \
} f>Td)s1 M
} uYO|5a<f~
6iezLG5
//日志 PFSLyV*
public static void log(String sMsg) W=}Okq)x9I
{ /!FWuRe^
System.err.println(sMsg); *=F(KZ
} h\[\\m O
AD5) .}[F
WPuz]Ty
public static void log(int sMsg) /)|X.D
{ v@ C,RP9
System.err.println(sMsg); 7()?C}Ni-
} gz#4{iT~
} 5rxA<Gs
]5CNk+`'
@ CsV]97`
/* ,lN5,zI=S
**TestMethod.java / l>.mK()
*/ jB$SUO`*
package NetFox; g;p)n
H3/caN:
~fN%WZ;_
public class TestMethod { `d]Z)*9
3SG?W_
*U7%|wd
public TestMethod() 3-Bl
{ ///xx/weblogic60b2_win.exe YZ}cB
try{ K\!#4>yd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C*Vd-U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 42) mM#
SiteFileFetch fileFetch = new SiteFileFetch(bean); *b(wVvz
fileFetch.start(); 4n( E;!s
} ^J=hrYGA
catch(Exception e){e.printStackTrace ();} 6o&ZIYJ9k
oh8L`=>&a
PBqy F
} +",S2Qmo
{5Lj8N5
6.Ie\5-a;
public static void main(String[] args) &]p}+{ (>
{ ".2K9j7$
new TestMethod(); f_mhD dq
} .QWhK|(.!
} =jAFgwP\
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