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)); (Dr g
} IUco 8
for(int i=0;i<nEndPos.length-1;i++) Nx~9Ug
{ |zD{]y?S-
nEndPos = nStartPos[i+1]; Pl_4;q!$
} ZhqrN]x
nEndPos[nEndPos.length-1] = nFileLength; rzJNHf=FVY
} =5NrkCk#V
} 5'f4=J$Z)
Z$R6'EUb1
9-;ujl?{
//启动子线程 R<VNbm;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [%(}e1T(
for(int i=0;i<nStartPos.length;i++) P(I`^x
{ 'P{0K?{H-4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gakmg#ki
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qms+s~oA
nStartPos,nEndPos,i); qbjBN z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ov1$7 r@
fileSplitterFetch.start(); /0Q=}:d
} y,&UST
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C3kxw1*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); m9bR %j
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "KQ3EI/g
nEndPos = " + nFileLength); zoXCMBg[
// fileSplitterFetch[nPos.length-1].start(); 5b X*8H D
!@mV$nTA
dkTj KV
//等待子线程结束 T"1H%65`V
//int count = 0; <ijf':X=*
//是否结束while循环 1@Dp<Q
boolean breakWhile = false; 3V:{_~~
`]^0lD=eI
}qy,/<R
while(!bStop) OjxaA[$
{ ~ZeF5
write_nPos(); (9:MIP
Utility.sleep(500); 6@pPaq6
breakWhile = true; xW@y=l Cu
`ER">@&
O+I\Q?
for(int i=0;i<nStartPos.length;i++) +jzwi3B`
{ n:JWu0,h
if(!fileSplitterFetch.bDownOver) cW B>
{ $0WO 4C%M
breakWhile = false; 68ce+|
break; TWF6YAQm
} RAMkTS
} x)eYqH~i
if(breakWhile) ,KvF:xqA
break; Uc,D&Og
$qkVu
s%h|>l[lKT
//count++; 0r?975@A
//if(count>4) Oo'IeXQ9(
// siteStop(); zbHNj(~
} q)%F#g
"Y(stRa
yl|?+
System.err.println("文件下载结束！"); f%n],tE6
} o>rsk 6lNi
catch(Exception e){e.printStackTrace ();} Jy&O4g/'5
} [{.e1s<EK
Q 6djfEN>
OiI[w8
//获得文件长度 #<ppiu$
public long getFileSize() r|$@Wsb?#
{ ~(E.$y7P
int nFileLength = -1; }{>)2S
try{ j8p</gd
URL url = new URL(siteInfoBean.getSSiteURL()); qfp,5@p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b&:>v9U
httpConnection.setRequestProperty("User-Agent","NetFox"); +a$'<GvP
#/fh_S'Z
O~t]:p9_
int responseCode=httpConnection.getResponseCode(); 4]L5%=atn
if(responseCode>=400) d-e6hI4b
{ b-pZrnZ!
processErrorCode(responseCode); '6l4MR$j&m
return -2; //-2 represent access is error ^z&eD,
} -2NXQ+m ;
{)j~5m.,/o
Oax*3TD
String sHeader; #+)AIf
I&9_F%rX
"YU<CO;4VV
for(int i=1;;i++) 8bQ\7jb
{ l*^J}oY
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W[trsFP1?
//Utility.log(in.readLine()); @tQu3Rq@
sHeader=httpConnection.getHeaderFieldKey(i); 3vx5dUgl,
if(sHeader!=null) )?35!s6
{ AF ,*bb
if(sHeader.equals("Content-Length")) Rf*we+
{ RTN?[`
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); (,Zy2wr=
break; y/}[S@4uB
} zrt\]h+
} o+UCu`7e
else +O`3eP`u
break; <a9<rF =r
} L%G/%*7;c
} VyQ@. Lm
catch(IOException e){e.printStackTrace ();} H CKD0xx
catch(Exception e){e.printStackTrace ();} ;Du+C%
8K: RoR
bI~ R6o
Utility.log(nFileLength); WZz8VF
^PwZP;On
#_]/Mr1
return nFileLength; '@4Myg* b
} Hh^EMQk
S0,q@LV
!*2cK>`
//保存下载信息（文件指针位置） K%NNw7\A
private void write_nPos() ZL!,s#
{ Ze `=n
try{ bf1Tky=/
output = new DataOutputStream(new FileOutputStream(tmpFile)); +tsF.Is!t
output.writeInt(nStartPos.length); _5<d'fBd
for(int i=0;i<nStartPos.length;i++) GyU9,>|~T
{ XO[S(q
// output.writeLong(nPos); W5C8$Bqm
output.writeLong(fileSplitterFetch.nStartPos); {wUbr^
output.writeLong(fileSplitterFetch.nEndPos); !O;su~7
} Q;9-aZ.H
output.close(); C\%T|ZDE
} tK@|sZ>3\
catch(IOException e){e.printStackTrace ();} "*08?KA
catch(Exception e){e.printStackTrace ();} %6A."sePO
} <( "M;C3y
Hzm<KQ g
?D 8<}~Do
//读取保存的下载信息（文件指针位置） 3y&N}'R(F
private void read_nPos() Fjnp0:p9X
{ 'p%aHK{
try{ m+66x {M2c
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %:yp>nm
int nCount = input.readInt(); Eb 8vnB#
nStartPos = new long[nCount]; s &4k
nEndPos = new long[nCount]; <x&0a$I
for(int i=0;i<nStartPos.length;i++) ie<zc+*rW
{ tX'`4!{@+
nStartPos = input.readLong(); a1^CpeG~
nEndPos = input.readLong(); h%4aL38
} \!O3]k,r
input.close(); UA>3,|gV1
} '6^+|1
catch(IOException e){e.printStackTrace ();} \"]KF8c^_
catch(Exception e){e.printStackTrace ();} eBlWwUy*6f
} gMXs&`7P
]~a;tF>Fw
&%@e6..Ex
private void processErrorCode(int nErrorCode) rV{:'"=y-
{ 1omjP`]|,
System.err.println("Error Code : " + nErrorCode); TJYup%q
} rcq^mPdQ
G909R>
EY$Dtb+g8
//停止文件下载 pm2-F]
public void siteStop() QoLp$1O(y
{ ?L K n
bStop = true; =*0KH##%$
for(int i=0;i<nStartPos.length;i++) ar&j1""
fileSplitterFetch.splitterStop(); }-Ds%L
`efC4#*!!
"Wz8f
} ,S(s
} MX7Ix{
//负责部分文件的抓取 3EY m@oZj
**FileSplitterFetch.java 23`salLclG
*/ yFQaNuZPC
package NetFox; h z{--
+R HiX!PG
O>a1S*mxP
import java.io.*; r]DU
import java.net.*; +`>E_+Mp
=Y6W Qf
?Tu=-ppw
public class FileSplitterFetch extends Thread { e84%Y8,0
EzjK{v">
Ip=QtNW3\
String sURL; //File URL ^blw\;LB
long nStartPos; //File Snippet Start Position o$Nhx_F
long nEndPos; //File Snippet End Position %dq%+yw{%m
int nThreadID; //Thread's ID |YyNqwP`,
boolean bDownOver = false; //Downing is over >~Tn%u<
boolean bStop = false; //Stop identical #\n*Qg4p
FileAccessI fileAccessI = null; //File Access interface "VSx?74q
|9IOZ>H9
!K}W.yv,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException knph549
{ rxyeix
this.sURL = sURL; ]&q<O0^'
this.nStartPos = nStart; 6o\uv
this.nEndPos = nEnd; l"nS+z
nThreadID = id; |pWu|M _'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m*N8!1Ot
} ]H}2|~c
$,U/,XA {E
~wv$uL8y
public void run() "G.X=, V
{ g)r{LxT#+
while(nStartPos < nEndPos && !bStop) Dv/7w[F
{ ,zHL8SiTX
=mZYBm,IQ
j=M%*`@
try{ c!7WRHJE_a
URL url = new URL(sURL); -aok]w m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g@4~,
httpConnection.setRequestProperty("User-Agent","NetFox"); d4\JM 65
String sProperty = "bytes="+nStartPos+"-"; ``:[Jr&
httpConnection.setRequestProperty("RANGE",sProperty); `NgQ>KV!
Utility.log(sProperty); 5>0\=
MkJBKS
Y3&,U
InputStream input = httpConnection.getInputStream(); MQN~I^v3
//logResponseHead(httpConnection); Ti_G
^GY^g-R
jmaw-Rx
byte[] b = new byte[1024]; @!!u>1
int nRead; 1@t.J>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0q-lyVZ^X
{ * BR#^Wt
nStartPos += fileAccessI.write(b,0,nRead); a?r$E.W'&
//if(nThreadID == 1) d!R+-Fp
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }Cw,m0KV/
} PLs`Ci|`
X coPkW
0'pB7^y
Utility.log("Thread " + nThreadID + " is over!"); @- |G_BZ
bDownOver = true; Pm)*zdZ8
//nPos = fileAccessI.write (b,0,nRead); JP6 Noia
} aaY AS"/:
catch(Exception e){e.printStackTrace ();} O]=jI
} %?gG-R
} hwXsfh |
16 `M=R
:AztHf?X
//打印回应的头信息 ^t gjs$M|
public void logResponseHead(HttpURLConnection con) _h}(jEd!
{ 67Pmnad
for(int i=1;;i++) ,>6a)2xh
{ IP#vfM
String header=con.getHeaderFieldKey(i); )?#K0o[<
if(header!=null) MW rhVn{R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MjC<N[WO>N
Utility.log(header+" : "+con.getHeaderField(header)); _yN5sLLyb
else c{y'&3\
break; Fh)xm* u(
} V>)/z|[
} `Ze$Bd\
eUNaq&M
\HzmhQb+m
public void splitterStop() 7MrHu2rZ=
{ }9\6!GY0
bStop = true; 5O]tkHYR
} ?B ,<gen
v0)Y,hW
O8\f]!O(
} "QXnE^
hizM}d-"C
56s%Qlgx
/* 5"57F88Y1
**FileAccess.java uNuFD|aQ.
*//文件访问(定位，写) KM[0aXOtv
package NetFox; ZXb{-b?[`
import java.io.*; hv#$Zo<
aB;f*x
MFa/%O_*
public class FileAccessI implements Serializable{ LBD],Ba!
qdpi-*2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L)U*dY
RandomAccessFile oSavedFile; MCibYvc[
long nPos; [sH3REE1h
9rz$c, Y(
n^{h@u
public FileAccessI() throws IOException 80Hi v
{ J'ce?_\?PY
this("",0); {c3FJ5:
} 9VTAs:0D=
4s:M}=]N
iupkb
public FileAccessI(String sName,long nPos) throws IOException D%3$"4M7!
{ D ON.)F
oSavedFile = new RandomAccessFile(sName,"rw"); `!N}u
this.nPos = nPos; cOdRb=?9
oSavedFile.seek(nPos); QpQ2hNf
} (Ox&B+\v+v
5L2j,]
^cPVnl
public synchronized int write(byte[] b,int nStart,int nLen) TEo
{ *V:U\G
int n = -1; %>+lr%B
try{ '"7b;%EN'
oSavedFile.write(b,nStart,nLen); N{g7
n = nLen; ,sc#l<v
} ~),%w*L
catch(IOException e) 7Dssr [
{ rG~W=!bj
e.printStackTrace (); (@*|[wN
} %fS1gSfh
4.,|vtp
*jc >?)k
return n; -:d{x#
} t*Ro2QZ
X:`=\D
rU9")4sQ
} |*J;X<Vm
}OcrA/
0&NM=~
/* (T2HUmkQ6
**SiteInfoBean.java :,p3&2I
*/ 11QZ- ^
package NetFox; oq|o"n)~
rC|nE=i
@+M1M2@Xz
public class SiteInfoBean { q'H6oD`
7ZAxhFC
6v:L8t$"
private String sSiteURL; //Site's URL "dndhoMq
private String sFilePath; //Saved File's Path _+)OL-
private String sFileName; //Saved File's Name K($+ILZ
private int nSplitter; //Count of Splited Downloading File 7`L]aRS[
D?1fY!C:r
$xZ ~bE9
public SiteInfoBean() 4($"4>BA
{//nSplitter的缺省值为5 B+`4UfB]Z}
//default value of nSplitter is 5 )xyjQ|b
this("","","",5); %r(WS_%K|
} BNNM$.ZIQ
rnj$u-8
u3+B/ 5x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) A,DBq9Z+4R
{ D1xGUz2r
sSiteURL= sURL; ]qv0Y~+`-K
sFilePath = sPath; >[|N%9\
sFileName = sName; '1ySBl1>
this.nSplitter = nSpiltter; vlbZ5
E^F<"mL*
_=s9o/Cn]
} -Y/i h(I^
N~O3KG q
dn- [Gnde
public String getSSiteURL() f<@!{y2Xe
{ GmWr
return sSiteURL; P+hcj p*
} ~/`/r%1/J
&su'znLV
1}DA| !~
public void setSSiteURL(String value) mg'q-G`\<
{ c("|xe
sSiteURL = value; zg<-%r'$
} . |T=T0^
B]"`}jn
^_bG{du
public String getSFilePath() Bxm,?=h
{ 2P"9m
return sFilePath; <(lA CH
} =WY'n l'
1z-.e$&z
Kt_oo[ey{
public void setSFilePath(String value) +r8bGS]ki
{ &*<27-x
sFilePath = value; $5&%X'jk
} {\[Gl
\tI%[g1M
~U]g;u
public String getSFileName() ljNwt
{ ! dzgi:
return sFileName; c}o 6Rm50
} "17)`Yf
f)/Z7*Z
+{I_%SsG
public void setSFileName(String value) !'jq.RawP
{ ^U_T<x8{
sFileName = value; !,[#,oy;
} yXR1NYg
`Y?VQ~ci>
K.)!qkW-%S
public int getNSplitter() w==BSH[
{ 4!Js="
return nSplitter; %hnBpz
} r<+C,h;aww
A#"Wk]jX
&$~fz":1!
public void setNSplitter(int nCount) C 5.3[
{ lhN@,q
nSplitter = nCount; ii)#(b:V
} K|7"YNohfG
} 15g!Q *v
,&t+D-s<f
O^@8Drgc
/* x4'@U<
**Utility.java 7s|'NTp
*/ I@'[>t
package NetFox; lYx_8x2
Zo3!Hs ZA
;l@94)@0
public class Utility { uks75W!}U
h:%,>I%{
d/7fJ8y8
public Utility() 2zBk#c+
{ J6Z[c*W
2Xt4Rqk$
u;`]U$Qq9
} OpUfK4U)
bWswF<y-
//线程睡眠 0WUBj:@g
public static void sleep(int nSecond) k)p`x"To
{ B@,r8)D
try{ .q@?sdGD
Thread.sleep(nSecond); &BVHQ7[
} Lzh8-d=HQ
catch(Exception e) \H] |5fp*
{ uAO!fE}CJ
e.printStackTrace (); >f]/VaMH{
} AjVC{\Ik
} @j46Ig4~b
Y=mr=]q
//日志 oPSPb(.
public static void log(String sMsg) H%wB8Y ]
{ Mg2+H+C~:
System.err.println(sMsg); ]&*POri&
} w$}q`k'
Nm*(?1
?XBdBR_"^
public static void log(int sMsg) iiPVqU%
{ X{-4w([
System.err.println(sMsg); s5VK
} NdXHpq;
} 0]DOiA
8?yIixhw
.hT>a<
/* O =Z}DGa+
**TestMethod.java \((iR>^|
*/ dfDjOZSL
package NetFox; I5Vn#_q+b
`0d0T~
jl,gqMn"V
public class TestMethod { ]*2),H1 c
c#OxI*,+/
? x%s j
public TestMethod() b;i*}4h!
{ ///xx/weblogic60b2_win.exe jBLTEb
try{ 22l'kvo4"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); z74JyY
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); PUdv1__C
SiteFileFetch fileFetch = new SiteFileFetch(bean); d<m;Q}/l&h
fileFetch.start(); uzd7v,
} PucNu8
catch(Exception e){e.printStackTrace ();} tr0b#4
H,7='n7"
"#d$$ 8
} 3lUVDNbZ
'P.y?
S<mZs;
public static void main(String[] args) ,1-%C)
{ Y+-yIMt$r
new TestMethod(); o|xf2k
} X`8<;l
} !sT>]e
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