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)); NX8hFwR
} 2"shB(:z>
for(int i=0;i<nEndPos.length-1;i++) Z'uiU e`&
{ rH,@"(p\
nEndPos = nStartPos[i+1]; j+3rS
} ?WqaT)l~
nEndPos[nEndPos.length-1] = nFileLength; 5`:d$rv
} 0y/31hp
} g)ZMU^1
sV5") /~
yZm=#.f
//启动子线程 @^ti*`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f52P1V]
for(int i=0;i<nStartPos.length;i++) d-m.aP)y:
{ $%M]2_W(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |v : )9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), XjP;O,x
nStartPos,nEndPos,i); imzPVGCD{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u)r:0;5
fileSplitterFetch.start(); SsZSR.tD
} Ac*J;fI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \/\w|j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .m\0<8C
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Wb cm1I)
nEndPos = " + nFileLength); <Uj9~yVN]
// fileSplitterFetch[nPos.length-1].start(); 7hu7rWY`E
b5Q>e%i#
kw#-\RR_c
//等待子线程结束 %QGw`E
//int count = 0; l1O"hd'~s
//是否结束while循环 uM,Ps}
boolean breakWhile = false; E,K>V:P*
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0b n%L~KU
while(!bStop) ,LSiQmV5
{ 4$ihnb`DQN
write_nPos(); 34N~<-9AY
Utility.sleep(500); wYV>Qd Z
breakWhile = true; ITn PF{N
3Z me?o*bY
~LOE^6C+~o
for(int i=0;i<nStartPos.length;i++) IFS_DW
{ q3h&V
if(!fileSplitterFetch.bDownOver) dT?3Q;>B?
{ T,>L
breakWhile = false; nfGI4ZE
break; kQlwl9
} %.$7-+:7A
} S++~w9}
if(breakWhile) Yc_(g0NK
break; H=f|X<8
SA=>9L,2
M3|G^q:l
//count++; :Y1;= W
//if(count>4) y@LiUe5
// siteStop(); esx/{j;<u
} SZ$WC8AX
W-&V:S{<
10c.#9$
System.err.println("文件下载结束！"); ,5ZQPICF
} =8<~pr-NO
catch(Exception e){e.printStackTrace ();} 3b]M\F9
} R)\^*tkz7
+DR$>a
=Tl_~OR
//获得文件长度 T{f$S
public long getFileSize() Qe ip h
{ ]PoWL;E'
int nFileLength = -1; B{:a,V7
try{ 0{8L^ jB/
URL url = new URL(siteInfoBean.getSSiteURL()); dY~z6bT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p)?6#~9$
httpConnection.setRequestProperty("User-Agent","NetFox"); fxr#T'i
{N/%%O.b
a\}MJ5]
int responseCode=httpConnection.getResponseCode(); xz5A[)N
if(responseCode>=400) c>^(=52Q
{ 3T gX]J@
processErrorCode(responseCode); 2ag8?#
return -2; //-2 represent access is error vxI9|i
} PcU~1m1
0('ec60u
Q3&q%n|<
String sHeader; !8cV."~
>-<iY4|[d
^V96lKt/
for(int i=1;;i++) hEsiAbTyF
{ {)!>e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +FqE fY4j
//Utility.log(in.readLine()); ,#&7+e!]>P
sHeader=httpConnection.getHeaderFieldKey(i); 5Lej_uqF
if(sHeader!=null) 51#OlvD
{ +)e|>
if(sHeader.equals("Content-Length")) (?JdiY/
{ ]SRpMZ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /9I/^i~
break; urjf3h[%
} 3)\fZYu)
} X|eZpIA45
else )S2yU<6oOt
break; _(kaaWJ
} 0.n[_?<(
} lNa+NtQu
catch(IOException e){e.printStackTrace ();} 1nskf*Z
catch(Exception e){e.printStackTrace ();} %>i:C-l8
y*vSt^
PMB4]p%o
Utility.log(nFileLength); Uza '%R
:Z6j5V;s
>5L_t
return nFileLength; ~qGW94
} 9N}\>L)_
5Q"w{ n
`a|&aj0
//保存下载信息（文件指针位置） !.$L=>:V
private void write_nPos() Op?"G
{ ^sLx3a
try{ Y6sX|~Zy
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8iJB'#''*
output.writeInt(nStartPos.length); x}?<9(nE c
for(int i=0;i<nStartPos.length;i++) Wx{E\ l
{ IyyBW2
// output.writeLong(nPos); p,$N-22a
output.writeLong(fileSplitterFetch.nStartPos); {.{Wl,|7
output.writeLong(fileSplitterFetch.nEndPos); |9c~kTjK
} #H>{>0q
output.close(); PKSfu++Z
} @3O)#r}\
catch(IOException e){e.printStackTrace ();} y-1e(:GF
catch(Exception e){e.printStackTrace ();} *<($.c
} ^1bslCe
M }d:B)cz
M[YFyM(
//读取保存的下载信息（文件指针位置） \BXzmok
private void read_nPos() +C{-s
{ mSxn7LG
try{ HN{c)DIm]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 3$k#bC
int nCount = input.readInt(); e;6KxvX~
nStartPos = new long[nCount]; UDg's
nEndPos = new long[nCount]; K?!qNK
for(int i=0;i<nStartPos.length;i++) IL %]4,
{ s51$x M
nStartPos = input.readLong(); J @"#
nEndPos = input.readLong(); 5h#h>0F
} .w.:o2L
input.close(); S v>6:y9?G
} k5.5$<< T
catch(IOException e){e.printStackTrace ();} e}e8WR=B
catch(Exception e){e.printStackTrace ();} ns8s2kYcm
} x 6`!
}bjZeh.
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private void processErrorCode(int nErrorCode) 3N+lWuE}K
{ cj8cV|8@
System.err.println("Error Code : " + nErrorCode); ,94<j,"
} zzQWHg]/
:;7I_tb
fo@^=-4A-
//停止文件下载 [s{!
public void siteStop() St-uE|8
{ y!77gx?-
bStop = true; WVy'f|3;
for(int i=0;i<nStartPos.length;i++) ~hLan&T
fileSplitterFetch.splitterStop(); ~-BF7f6C
Yv;s3>r
lrT2*$ w3
} \j>7x
} 37/n"\4
//负责部分文件的抓取 ?0VR2Yb${b
**FileSplitterFetch.java yJm"vN
*/ aKbmj
package NetFox; %T{]l;5
HB/V4ki
WVbrbs4
import java.io.*; Z.6dL
import java.net.*; hi0HEm\
' [ 4;QYw
G21o@38e
public class FileSplitterFetch extends Thread { yp.K-
z*eBjHbF
ATNOb
String sURL; //File URL +$,Re.WnP
long nStartPos; //File Snippet Start Position pE4a~:
long nEndPos; //File Snippet End Position k&]nF,f
int nThreadID; //Thread's ID Z',!LK!
boolean bDownOver = false; //Downing is over Ma[EgG
boolean bStop = false; //Stop identical &7aWVKon
FileAccessI fileAccessI = null; //File Access interface e`D}[G#
/~[Lr
1sQIfX#2f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~7P)$[
{ W7i|uTM
this.sURL = sURL; IU%|K~_n
this.nStartPos = nStart; NI >%v
this.nEndPos = nEnd; ):D"LC
nThreadID = id; ,^#Jw`w^
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yGZsNd {a&
} S(Yd.Sp
*U?O4E9
NB"S,\M0
public void run() HGDrH
{ l90mM'[
while(nStartPos < nEndPos && !bStop) 200yN+ec
{ ~U9K<_U
uepyH
qLN^9PdEE
try{ ,5}U H
URL url = new URL(sURL); }htjT/Nm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jVj5; }
httpConnection.setRequestProperty("User-Agent","NetFox"); tMIYVHGy
String sProperty = "bytes="+nStartPos+"-"; ]A#lV$
httpConnection.setRequestProperty("RANGE",sProperty); ^:eZpQ [,
Utility.log(sProperty); RK>Pe3<
K7+yU3
BM%wZ: s
InputStream input = httpConnection.getInputStream(); h+f>#O+:
//logResponseHead(httpConnection); 0B NLTRv
> VG
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byte[] b = new byte[1024]; AZtS4]4G)
int nRead; a|aVc'j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bLgH3[{
{ kNEEu!G
nStartPos += fileAccessI.write(b,0,nRead); Lsmcj{1d
//if(nThreadID == 1) C|(A/b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nV;'UpQw
} RgE`Hr
\oQ]=dDCd%
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Utility.log("Thread " + nThreadID + " is over!"); @ D+ftb/
bDownOver = true; 'Wonz<{'
//nPos = fileAccessI.write (b,0,nRead); ^u/%zL
} a^|DD#5
catch(Exception e){e.printStackTrace ();} dhl[=Y` Q
} g*|j+<:7
} %\As
\{,TpK.
W.7rHa
//打印回应的头信息 {|+Y;V`
public void logResponseHead(HttpURLConnection con) GP|=4T}Bf
{ R$awgSE
for(int i=1;;i++) IP~!E_e}\
{ ^4y]7p
String header=con.getHeaderFieldKey(i); =8kmFXo
if(header!=null) US6_5>/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 092t6D}
Utility.log(header+" : "+con.getHeaderField(header)); R$a<=
else \INH[X#>
break; !QUY (
} j=_rUc'Me
} K~x,so
&K)8
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public void splitterStop() wucdXj{%
{ VSj!Gm0LB
bStop = true; ~xH&"1
} +Q*`kg'
!,WGd|oJ
TBhM^\z
} 30Yis_l2h
bdUPo+
"}]`64?
/* # kI>
**FileAccess.java cH]tZ$E`
*//文件访问(定位，写) dn6B43w
package NetFox; KWwtL"3
import java.io.*; T X`X5j
xS18t="
)vr@:PE
public class FileAccessI implements Serializable{ j)1yv.
@u3`lhUcT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^6 6!f 5^W
RandomAccessFile oSavedFile; LHAlXo;
long nPos; :NzJvI<
Ycm)PU["
R+sT &d
public FileAccessI() throws IOException @nxo Bc !P
{ R{hX--|j
this("",0); bIKg>U'5d
} o3ZN0j69|
'Pz%c}hJ
]AP1+ &9fN
public FileAccessI(String sName,long nPos) throws IOException GnV0~?
{ <?jdNM
oSavedFile = new RandomAccessFile(sName,"rw"); yu?5t?vf
this.nPos = nPos; XGlt^<`
oSavedFile.seek(nPos); Fc[KIG3@
} $o"nTl
k<1yv$/mW
QWmE:F[M~
public synchronized int write(byte[] b,int nStart,int nLen) @|!4X(2
{ |J`EM7qMK
int n = -1; TyxIlI4"
try{ :-&|QVH
oSavedFile.write(b,nStart,nLen); -"(*'hD
n = nLen; U%{GLO
} G#iQX`
catch(IOException e) A#uU]S
{ WlL(NrVA@@
e.printStackTrace (); 2FcL-?
} 4Nm>5*]
>hKsj{=R7
3f|}p{3
return n; mDD.D3RS
} fV:15!S[
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gW,[X(
} a+h$u
<+8'H:wz
K/4@2vF
/* ^5 >e
**SiteInfoBean.java U}v`~'K
*/ :I"CQ C[Z
package NetFox; 2 a<\4w'
3WV(Ok
ycGY5t@K@
public class SiteInfoBean { *0WVrM06?
Tw~R-SiS`s
:\TMm>%q
private String sSiteURL; //Site's URL >T$0*7wF
private String sFilePath; //Saved File's Path W?7l-k=S
private String sFileName; //Saved File's Name G1:}{a5i_
private int nSplitter; //Count of Splited Downloading File s"(RdJ-,
*k$[/{S1-
~cz}C("Z
public SiteInfoBean() !}*N';
{//nSplitter的缺省值为5 <H[w0Z$
//default value of nSplitter is 5 \u=d`}E
this("","","",5); `At.$3B
} 2Gyq40
$CcjuPsK
%wD#[<BGn>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yCX5 5:
{ l\U Q2i
sSiteURL= sURL; 'Kelq$dn#
sFilePath = sPath; 68%aDs
sFileName = sName; *4O=4F)x
this.nSplitter = nSpiltter; Wzq W1<*`
5C w( 4.
egmUUuO
} zcpL[@B
u#05`i:Z
!_glZ*tL
public String getSSiteURL() Q+CJd>B
{ ; :e7Z^\/k
return sSiteURL; [V}vd@*k
} :4AQhn^;"
Fwm$0=BXL
QE]@xLz
public void setSSiteURL(String value) l;F"m+B!$
{ ZvY"yl?e
sSiteURL = value; x/QqG1q
} s|YH_1r
h yrPu_
0 _!0\d#c
public String getSFilePath() uJ`N'`Z
{ M-WSdG[AJ
return sFilePath; ulR yt^bx|
} SH*'<
^Z (cVg
/E>;O47a
public void setSFilePath(String value) zzG=!JR
{ PW*Vfjf4
sFilePath = value; DJ ru|2
} B<W}:>3
+'H[4g`
X[z;P!U
public String getSFileName() ^}j~:EZb
{ ODJ"3 J
return sFileName; N=mvr&arP
} KFM[caKeJO
q4BXrEOw
'r'=%u$1C
public void setSFileName(String value) &oL"AJU
{ xvGYd,dlK
sFileName = value; z/Lb1ND8
} 88Pt"[{1
hV3]1E21"
g4W$MI
public int getNSplitter() (lsG4&\0F
{ b+s'B4@rb
return nSplitter; ui]iOp
} q NGR6i
4S(G366
6v@Prw@.b
public void setNSplitter(int nCount) /N0mF< P
{ +o+f\!
nSplitter = nCount; K#FD$,c~
} L1IF$eC
} vbJ<|#|r-
6/!:vsa"3
288mP]a(v_
/* mF gqM:
**Utility.java zJ`u>:*$
*/ ,7nu;fOT[
package NetFox; (nqhX<T>
jMT[+f
r$<!?Z
public class Utility { -J]?M
%6ckau1_;
}3 /io0"D
public Utility() J~x]~}V&
{ t!D'ZLw
rpk8
St;9&A
} M]8>5Zx.
AB=%yM7V*
//线程睡眠 `n+uA~
public static void sleep(int nSecond) !&%KJS6p4
{ pI@71~|R
try{ kn#?+Q
Thread.sleep(nSecond); 9WHE4'Sa
} l4gH]!/@
catch(Exception e) q\tr&@4iC
{ ?M90K)&g{
e.printStackTrace (); +kI}O*s
} 6>?qBWW
} qMaO1cE\
hC-uz _/3
//日志 P, x"![6
public static void log(String sMsg) |E13W
{ k(f),_
System.err.println(sMsg); 1P]J3o
} F%L"Q>aHW
Eu|/pH=:
fMwF|;
public static void log(int sMsg) lB}?ey
{ s.(.OXD&
System.err.println(sMsg); y9}qB:[bR
} W *0!Z:?
} 4n#u?)
H Qj,0#J)
y^r'4zN'
/* ]n=z(2Z9lD
**TestMethod.java ?`TQ!m6y
*/ o.$48h(
package NetFox; .p{lzI9
h`Jc%6o
<mX5VGY9^
public class TestMethod { J rK{MhO
dC<%D'L*
h5{//0 y
public TestMethod() >MJ%6A>
{ ///xx/weblogic60b2_win.exe hMupQDv/I
try{ {F_>cyR
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *b;)7lj0h
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2?(/$F9X,
SiteFileFetch fileFetch = new SiteFileFetch(bean); $d1ow#ROgy
fileFetch.start(); xpZ@DK;
} l>jrY1u
catch(Exception e){e.printStackTrace ();} %n]jsdE^|
+R?E @S
`LH9@Z{
} t:dvgRJt*
QAI=nrlp
,T;sWl
public static void main(String[] args) bLTX_ R
{ d%@0xsU1
new TestMethod(); VK4UhN2
} l="(Hp%b
} qY&(O`?m&
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