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)); b!l/O2 G
} ,b${3*PPQ
for(int i=0;i<nEndPos.length-1;i++) yv+DM`0
{ X"fSM #
nEndPos = nStartPos[i+1]; ;p8,=w
} wK*b2r}0/
nEndPos[nEndPos.length-1] = nFileLength; "raC?H
} ^2<nn op
} z@tIC^s
oc0z1u
=JDa[_lpN
//启动子线程 hcrx(oJ5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !fT3mI6u\
for(int i=0;i<nStartPos.length;i++) )K>2
{ I]jK]]@
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S!{Kn ;@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tLc~]G*\`s
nStartPos,nEndPos,i); jHx)q|2\
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?S0gazZm
fileSplitterFetch.start(); y^tp^
} \?K>~{)
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), mEVne.D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g| M@/Dl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ^hIKDc!.m
nEndPos = " + nFileLength); 4SGF8y@WU
// fileSplitterFetch[nPos.length-1].start(); t=6Wk4
SHt#%3EU
8pE0ANbq
//等待子线程结束 <f/wWu}
//int count = 0; RxrUnMF
//是否结束while循环 YA'_Ba(v)
boolean breakWhile = false; jb {5
w@Gk#
h_?#.z0ih;
while(!bStop) KGq4tlM6
{ P6([[mmG
write_nPos(); 3^%sz!jK+
Utility.sleep(500); FK!UUy;
breakWhile = true; )WR*8659e
{WYmO1
*JmU",X
for(int i=0;i<nStartPos.length;i++) <Q%:c4N
{ ?[~)D}] j
if(!fileSplitterFetch.bDownOver) v>]^wH>/"
{ N \Wd0b
breakWhile = false; W*D].|
break; m<wEw-1.
} B9Z=`c.T
} ckg8x&Z
if(breakWhile) `ek On@T0
break; R`F8J}X_
.|Bmg6g*
[ Cu3D
//count++; /{7we$+,p
//if(count>4) AYLCdCoK.
// siteStop(); ].,TSnb
} /*2sg>e'QF
@[] A&)B
{V*OYYI`R
System.err.println("文件下载结束！"); k w]m7T
} eHy.<VX
catch(Exception e){e.printStackTrace ();} i<]Y0_?s
} AG==A&d>$
W;9Jah.
%G>|u/:U
//获得文件长度 k3FpD=N
public long getFileSize() 0-{l4;o
{ G*$a81dAX
int nFileLength = -1; VtJy0OGcRP
try{ t1h2ibO
URL url = new URL(siteInfoBean.getSSiteURL()); TPeBb8v8D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {cF>,T
httpConnection.setRequestProperty("User-Agent","NetFox"); OJH:k~]0!
6"UL+$k
dS[="Set
int responseCode=httpConnection.getResponseCode(); xFcRp2W9R
if(responseCode>=400) eS{ xma
{ GOeYw[Vh
processErrorCode(responseCode); U~Ai'1?xz
return -2; //-2 represent access is error $={WtR
} [va7+=[1=
t<Z)D0.
\p&a c&]
String sHeader; $3C$])k
UIl^s8/
F< #!83*%
for(int i=1;;i++) mp x/~`c
{ Q(e3-a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 0Q_@2
//Utility.log(in.readLine()); al3[Ph5G
sHeader=httpConnection.getHeaderFieldKey(i); nPj/C7j
if(sHeader!=null) LpJ_HU7@lk
{ $*u{i4b
if(sHeader.equals("Content-Length")) <Gr775"
{ }nW)+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,UD,)ZPf[
break; ecI[lB
} E*t0ia8
} &_!g|-
else bCmhlSNi
break; aF'9&A;q
} t,8p}2,$
} tR]1c
catch(IOException e){e.printStackTrace ();} # Y*cLN`Y7
catch(Exception e){e.printStackTrace ();} jSj (ZU6
}Pj3O~z
1jhGshhp
Utility.log(nFileLength); 1K;i/
$*Q_3]AY]
$K,6!FyBa
return nFileLength; |5}~n"R5
} q&-A}]
V %cU@
]v^;]0vcr
//保存下载信息（文件指针位置） U/JeEI%L
private void write_nPos() @zJhJ'~Sl
{ AjQ^ {P
try{ M zLx2?
output = new DataOutputStream(new FileOutputStream(tmpFile)); I2!0,1Q
output.writeInt(nStartPos.length); 8'2lc
for(int i=0;i<nStartPos.length;i++) PG1#Z?_
{ s)e; c<(/
// output.writeLong(nPos); 3-Q*umh
output.writeLong(fileSplitterFetch.nStartPos); `aS9o]t
output.writeLong(fileSplitterFetch.nEndPos); g]g2`ab |
} (zFUC]
output.close(); V+()`>44
} oj7X9~ nd
catch(IOException e){e.printStackTrace ();} _`JYA
catch(Exception e){e.printStackTrace ();} <h/\)bPB
} oK GFDl]3
jaAv_=93f
U/B1/96lJ
//读取保存的下载信息（文件指针位置） $rySz7NI
private void read_nPos() ^;2dZgJ4^
{ <N%8"o
try{ \Mv8pU
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;n*N9-|.
int nCount = input.readInt(); O/IW.t
nStartPos = new long[nCount]; qO<'_7TN[
nEndPos = new long[nCount]; xy%lp{
for(int i=0;i<nStartPos.length;i++) ua['rOnU
{ dQ8}mH!
nStartPos = input.readLong(); {.N" 6P
nEndPos = input.readLong(); #lax0IYY=
} #zcp!WE.OI
input.close(); <%JRZYZ
} ]]s_ 8u3
catch(IOException e){e.printStackTrace ();} X,/@#pSOz
catch(Exception e){e.printStackTrace ();} xw5E!]~D
} F6T@YSP
bp6 La`+
$a6&OH/
private void processErrorCode(int nErrorCode) [)`9euR%
{ *|x2"?d-F:
System.err.println("Error Code : " + nErrorCode); -#b-@sD
} -;z&">
Q^v8n1
*n0k2 p
//停止文件下载 WT!8.M;Kv
public void siteStop() #[*e$C
{ FeS6>/
bStop = true; -/aDq?<<
for(int i=0;i<nStartPos.length;i++) /h0<0b?i
fileSplitterFetch.splitterStop(); kRgyvA,*;
{sy#&m(el
g S;p::
} u pf7:gk +
} {MKq Yl{
//负责部分文件的抓取 *g5df[
**FileSplitterFetch.java lC6#EU;
*/ J-fU,*Bk
package NetFox; c7IgndVAV
sHe:h XG'
'?Q [.{<
import java.io.*; &_&])V)<\S
import java.net.*; `X]-blHo
F'Fc)9qFa<
WjGv%^?
public class FileSplitterFetch extends Thread { J%xp1/=2
.9WUp>
|rf\]3 F
String sURL; //File URL gtz!T2%
long nStartPos; //File Snippet Start Position hX=+%^c%_A
long nEndPos; //File Snippet End Position qJW>Y}
int nThreadID; //Thread's ID DRi!WWivn
boolean bDownOver = false; //Downing is over muo7KUT
boolean bStop = false; //Stop identical 1uv"5`%s
FileAccessI fileAccessI = null; //File Access interface hE!3kaS
doXd6q4H
E8>npDFv.
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3l>P>[<o
{ IqEY.2KN
this.sURL = sURL; Tm_vo-
this.nStartPos = nStart; f9D7T|J?10
this.nEndPos = nEnd; \+v_6F
nThreadID = id; b0E(tPw5c
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "twV3R
} @?K(+BGi
>}<:5gZtA
7%8,*T
public void run() -z0,IYG }
{ [j}%&$
while(nStartPos < nEndPos && !bStop) ~SZ0Yu:X
{ n<lU;
wH!]B-hn
8ne'x!1 D
try{ _Ux>BJmP
URL url = new URL(sURL); W1y,.6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kOR%<#:J
httpConnection.setRequestProperty("User-Agent","NetFox"); 8pDJz_F!{
String sProperty = "bytes="+nStartPos+"-"; .Rc&EO
httpConnection.setRequestProperty("RANGE",sProperty); [O [N_z
Utility.log(sProperty); 4ej$)AdW3
Qoq@=|7kxa
g@nk0lQewj
InputStream input = httpConnection.getInputStream(); + 7E6U*
//logResponseHead(httpConnection); /D8cJgH-
+zs;>'Sf
<g,k[
byte[] b = new byte[1024]; O(/K@e
int nRead; 1WcT>_$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) J~<:yBup}
{ 4pq>R
nStartPos += fileAccessI.write(b,0,nRead); ?Dm!;Z+7
//if(nThreadID == 1) H:9( XW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DfV_08
} wGISb\rr
ffm19B=
AGCqJ8`|T
Utility.log("Thread " + nThreadID + " is over!"); RPaB4>
bDownOver = true; m^T$H_*;
//nPos = fileAccessI.write (b,0,nRead); 6Om-[^
} Ko''G5+
catch(Exception e){e.printStackTrace ();} FPFt3XL
} <2H0m
} %DPtK)X1
$j{ynh)^
R) @k|
//打印回应的头信息 d-N<VVcy\
public void logResponseHead(HttpURLConnection con) ])~*)I~Y
{ Q6%m}R
for(int i=1;;i++) K]kL?-A#'
{ W .Hv2r3
String header=con.getHeaderFieldKey(i); l*'jqR')h^
if(header!=null) `?=AgGg
//responseHeaders.put(header,httpConnection.getHeaderField(header)); qg.[M*
Utility.log(header+" : "+con.getHeaderField(header)); .Ji r<"*<
else P$]Vb'Fz
break; g-}Vu1w0{6
} ,fET.s^|U
} ,Z>RvLl
_7$j>xX
0yAvAx
public void splitterStop() Jz:d\M~j5
{ s977k2pp-
bStop = true; lrq !}\aX
} 2[M:WZ.1
&g) `
m(g$T
} :?RK>}4|F
S~Q7>oNm
Z/beROW)
/* wM!QU{Lz
**FileAccess.java A|Y\Y}
*//文件访问(定位，写) y62;&{?m
package NetFox; ItOVx!"@9
import java.io.*; 5QSd$J
k92X)/ll'
%WCpn<)
public class FileAccessI implements Serializable{ |UR.7rOV
8zVXQ!'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &]vd7Q.t
RandomAccessFile oSavedFile; u3k+Xg:
long nPos; XkdNWR0
$AsM 9D<BE
3\D jV2t
public FileAccessI() throws IOException 5>A3;P
{ iNQk{n
this("",0); $(zJ
} ZibHT:n
j*xens$)
`fc*/D
public FileAccessI(String sName,long nPos) throws IOException &Puu Xz<
{ fG,qax`:c
oSavedFile = new RandomAccessFile(sName,"rw"); Vs07d,@w>
this.nPos = nPos; PCaa_ 2
oSavedFile.seek(nPos); C|!E'8Rw
} >Q+EqT
|qbJ]v!
k+i}U9c"
public synchronized int write(byte[] b,int nStart,int nLen) NqF-[G<
{ mup3ua]!
int n = -1; h{PLyWH
try{ /pb7
oSavedFile.write(b,nStart,nLen); #Wc)wL-Tg
n = nLen; bJBx~
} 3`e1:`Hu
catch(IOException e) `kj7I{'l%9
{ Yhlk#>I
e.printStackTrace (); &kO4^ A
} Xq)'p8C?
>nr1|2
{g )kT_
return n; :'!?dszS
} cL1cBWd
7<1Y%|x`
4]dPhsey
} m CdkYN#
E&K8hY%5
fp>o ^+VB
/* CWDo_g$
**SiteInfoBean.java %5z88-\
*/ >eRbasshEI
package NetFox; %pg*oX1VK6
)m)>k` 0
~RMOEH.o
public class SiteInfoBean { Gu_s:cgB9F
Y":hb;&
VUt 6[~?
private String sSiteURL; //Site's URL Qu;AU/Q<([
private String sFilePath; //Saved File's Path G&n_vwZ%
private String sFileName; //Saved File's Name 2qn~A0r
private int nSplitter; //Count of Splited Downloading File _`D_0v(X
KM\`,1?x92
f%|g7[
public SiteInfoBean() GuS3O)6Sg
{//nSplitter的缺省值为5 .OWIlT4K
//default value of nSplitter is 5 Jp,ohVRNq
this("","","",5); Nm^q.)dO
} {_ 1q`5o
W&p-Z"=)
j?8E >tM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _@RW7iP>
{ cdGl[dQ/
sSiteURL= sURL; 0 /H1INve
sFilePath = sPath; 1zp,Suv
sFileName = sName; }h]:I'R!
this.nSplitter = nSpiltter; f,uxoAS
9g*~X;`2
{9=U6m^R2
} Tw`l4S&
Hv IN'
p,1RRbyc
public String getSSiteURL() GdP9Uj)n-
{ tr'95'5W.
return sSiteURL; mC93 &0
} Q;^([39DI
y-Ol1R3:c#
hZJ Nh,,w
public void setSSiteURL(String value) /3c1{%B\
{ ^#Z(&/5f0
sSiteURL = value; Em?skUnG,
} /JfXK$`
k1cBMDSokO
#/1Bam6
public String getSFilePath() DV.MvFV
{ :?^(&3;
return sFilePath; ~\kRW6
} AV&ege
=AAH}
dZYS5_wr
public void setSFilePath(String value) +,KuYa{lu
{ +X- k)9
sFilePath = value; ![V<vIy
} +0a',`yc
p1D-Q7F
!C+25vup
public String getSFileName() Wx-{F
{ J7maG|S(DF
return sFileName; h*KhH>\
} Ln: y|t
Gs9jX/#
u*U?VZ5
public void setSFileName(String value) !eO?75/
{ m$cM+
sFileName = value; }@#eD
} dy0!Zz
0b|!S/*A3
O4#zsr:"
public int getNSplitter() 5QT9
{ 8q0 .yhb
return nSplitter; k+i=0P0mf
} -`gC?yff:
KA<
H_2hr[
public void setNSplitter(int nCount) <zUmcZ
{ +GGj*sD
nSplitter = nCount; 5eU/ [F9
} !Zwl9DX3
} Ue\&
2V0R|YUt
`2Z=Lp
/* /bb4nM_E/
**Utility.java }1>a71
*/ WU\):n
package NetFox; \\T I4A^#
p 2i5/Ly
b9vKux
public class Utility { K0v,d~+]
A<Na,EC
-OHG1"/
public Utility() /U`"|3
{ fvx0]of
V&>7i9lEz
b6i0_fOO
} E=B9FIx~<
COT;KC6 n
//线程睡眠 *?8Q:@:
public static void sleep(int nSecond) b 9?w _
{ 4VooU [Ka(
try{ qzLRA.#f^
Thread.sleep(nSecond); X}Csl~W8in
} (0][hdI~B
catch(Exception e) r9%W?fEBp
{ _Nj;Ni2rD
e.printStackTrace (); "K@os<
} v ;9s
} W,<Vr2J[
7}#vANm
//日志 r`krv-,O$
public static void log(String sMsg) {P]l{W@li
{ I;`V*/s8"
System.err.println(sMsg); ALG #)$|
} }cP3i
+j<Nu)0iY
7OZs~6(
public static void log(int sMsg) =:2V4H(F
{ 3)xV-Y9
System.err.println(sMsg); -{w&ya4X
} k-89(
} wS5hXTb"
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Wm A:"!~M
/* *7R3EUUk
**TestMethod.java 5p>a]gp
*/ z(]*'0)P
package NetFox; %1 v)rg y
(;n|>l?*
@M,_mX
public class TestMethod { 87HVD Di
15zL,yo
!At_^hSqz
public TestMethod() o#T,vu0s
{ ///xx/weblogic60b2_win.exe |9%>R*
try{ "[8](3\v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $nVTN.k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); V^0*S=N
SiteFileFetch fileFetch = new SiteFileFetch(bean); $'&5gFr9
fileFetch.start(); vxwctJ&
} }:BF3cH> 0
catch(Exception e){e.printStackTrace ();} USbiI%
06ueE\@Sg
)~5`A*Ku
} $DMeUA\av
/M#A[tZ3
'*T7tl
public static void main(String[] args) z><JbSE?
{ E u@TCw8@
new TestMethod(); >GjaA1,
} hVlL"w*1
} _W!g'HP-D
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