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)); d.j'0w"
} niEEm`"
for(int i=0;i<nEndPos.length-1;i++) 0o$HC86w
{ ;u};&sm
nEndPos = nStartPos[i+1]; M|#5gKXd
} H L|spl(c
nEndPos[nEndPos.length-1] = nFileLength; B=bI'S8\
} |id79qY7g
} I/V)z9
JX/4=..
,PMb9O\B
//启动子线程 .hlQ?\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7;}3{z
for(int i=0;i<nStartPos.length;i++) &<V_[Wh"
{ hY= s9\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BZ;}ROmqk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T E&Q6
nStartPos,nEndPos,i); b({Nf,(a2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QYTTP6 Gz+
fileSplitterFetch.start(); >6[ X }
} RQpIBsj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .eabtGO,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W-!Bl&jF[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", h lkvk]v
nEndPos = " + nFileLength); RCh$j&Tn
// fileSplitterFetch[nPos.length-1].start(); j[/SXF\=
(' Ko#3b
hX8gV~E=y
//等待子线程结束 MLt'YW^
//int count = 0; HZDaV&)@
//是否结束while循环 B)"#/@!bHH
boolean breakWhile = false; c{,y{2c]LT
[-E{}FL|
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while(!bStop) !u53 3
{ XSp x''l
write_nPos(); G9i&#)nWr
Utility.sleep(500); <84C tv
breakWhile = true; /lr1hW~Dbk
2q-:p8
aYaG]&hb
for(int i=0;i<nStartPos.length;i++) <+T\F;
{ '9-axIj70
if(!fileSplitterFetch.bDownOver) < QDr,Hj
{ b(#"w[|
breakWhile = false; HJfQ]p'nK2
break; mq J0z4I}
} R=vbUA
} 8h&oSOkQk,
if(breakWhile) I|g@W_
break; NK7H,V}T
{PODisl>\D
1V|< A
//count++; V3>f*Z)xn
//if(count>4) "x#]i aDjf
// siteStop(); (s}Rj)V[^
} AI1@-
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ZnvEv;P
System.err.println("文件下载结束！"); pqyWv;
} .'t (-eT,
catch(Exception e){e.printStackTrace ();} '1W!xQ}E
} 6=ZRn gQ
M82.khm~jM
S}oG.r 9
//获得文件长度 VHXI@UT*
public long getFileSize() K&=1Ap
{ ZYE' C
int nFileLength = -1; .S~@BI(|<
try{ A",eS6
URL url = new URL(siteInfoBean.getSSiteURL()); zKIGWH=qqm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !]$V9F{K
httpConnection.setRequestProperty("User-Agent","NetFox"); BZovtm3E
D:=t*2-Iv
9@:BK;Fi
int responseCode=httpConnection.getResponseCode(); _*O7l
if(responseCode>=400) X AQGG>
{ EkN_8(w
processErrorCode(responseCode); iI3v[S
return -2; //-2 represent access is error an3~'g?
} #v{Y=$L
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%b=Y <v
String sHeader; "hL9f=w
+"jl(5Q
!n|#|.0m
for(int i=1;;i++) ):e+dt
{ /+>)"D6'
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); H5~1g6b@
//Utility.log(in.readLine()); >xT^RYS
sHeader=httpConnection.getHeaderFieldKey(i); ,Kuk_@(}5~
if(sHeader!=null) ~|h lE z
{ {S G*
if(sHeader.equals("Content-Length")) +a|"{
{ J0=7'@(p
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y=r!2u6r~
break; ! 0^;;'
} VM7 !0
} .Y;b)]@f
else _IWxYp
break; )B6# A0
} _1ew(x2J
} HN{zT&
catch(IOException e){e.printStackTrace ();} aR _NyA
catch(Exception e){e.printStackTrace ();} ^oYPyk`9
zxkM'8JC
9CB\n
Utility.log(nFileLength); ]fZ<`w8u}
a5|@R<iF
o]<jZ_|gB
return nFileLength; E!zX)|Z<
} -ey)J +?t
pV7N byb4
B@ {&<
//保存下载信息（文件指针位置） A^ViDP
private void write_nPos() Z&Ue|Z4Qt
{ Z0-ytODII
try{ iRNLKi
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2:Q(Gl`<l
output.writeInt(nStartPos.length); ?Nf 5w
for(int i=0;i<nStartPos.length;i++) bHE7yv [
{ Fi4UaJ3K
// output.writeLong(nPos); ~M5:=zKQ
output.writeLong(fileSplitterFetch.nStartPos); R(G\wqHUT3
output.writeLong(fileSplitterFetch.nEndPos); 4/'N|c.
} 9#qeFBI
output.close(); z}+i=cAN
} ^]>aHz9
catch(IOException e){e.printStackTrace ();} m2xBS!fm
catch(Exception e){e.printStackTrace ();} E=AVrv5T
} -R0/o7
[}-3PpF
jAC78n,Fi@
//读取保存的下载信息（文件指针位置） W\8Ln>
private void read_nPos() BtsdeLj|
{ +Rwx%=
try{ e)@3m.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); &w85[zs
int nCount = input.readInt(); iidT~l
nStartPos = new long[nCount]; O,s.D,S
nEndPos = new long[nCount]; aC!EWgwW[
for(int i=0;i<nStartPos.length;i++) BMFF=
{ I[d]!YI}F
nStartPos = input.readLong(); F}Srn;V
nEndPos = input.readLong(); p=Y>i 'CG
} )h_8vO2
input.close(); 8Lz]Z h=ZU
} O=}g4c
catch(IOException e){e.printStackTrace ();} tU@zhGb
catch(Exception e){e.printStackTrace ();} eGL<vX
} ^YlI>_3s
QJGKQ2^ n
)OP){/
private void processErrorCode(int nErrorCode) 86 .`T l;
{ $IX\O
System.err.println("Error Code : " + nErrorCode); *if`/N-q(m
} {ci.V*:"
ru9zTZZD
Vzg=@A#
//停止文件下载 2C=Q8ayvX
public void siteStop() (xpn`NA
{ ~h$wH{-U#
bStop = true; h6:#!Rg
for(int i=0;i<nStartPos.length;i++) `3cCH
fileSplitterFetch.splitterStop(); xHA0gZf
>jg0s)RA'
m Y,|J\w@
} u<xo/=Z
} GVGlVAo|@
//负责部分文件的抓取 1q7tiMvV-
**FileSplitterFetch.java M@et6aud;K
*/ b KtD"JG\
package NetFox; nh+l78
D{8PQ2x>
p4!:]0c
import java.io.*; &7e)O=
import java.net.*; ]=pR
baV>N[F&
!]yO^Ob.E
public class FileSplitterFetch extends Thread { M5357Q
4GdX/6C.
MGS-4>Q#
String sURL; //File URL rwLAW"0Qz
long nStartPos; //File Snippet Start Position w8S!%abl1
long nEndPos; //File Snippet End Position &#`l;n:]+
int nThreadID; //Thread's ID YyAJ m^o
boolean bDownOver = false; //Downing is over Rhc-q|Lz8
boolean bStop = false; //Stop identical '7^M{y/dU
FileAccessI fileAccessI = null; //File Access interface x!LQxoNF
)SF}2?7e
:}8Z@H!KkY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException H %JaZ?(
{ {9Y+.46S
this.sURL = sURL; EP'h@zdz
this.nStartPos = nStart; y$FW$Ka
this.nEndPos = nEnd; vX0f,y
nThreadID = id; Q1d'~e
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x+ncc_2n&D
} hI%bjuq
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public void run() voP7"Dl[
{ )'17r82a
while(nStartPos < nEndPos && !bStop) "k*PA\U
{ IG)s^bP
::Ke^dp
kpL@P oQ/r
try{ EVp,Q"V]
URL url = new URL(sURL); j 8*ZF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S}APQ
httpConnection.setRequestProperty("User-Agent","NetFox"); *.L81er5~
String sProperty = "bytes="+nStartPos+"-"; #e' }.4cr
httpConnection.setRequestProperty("RANGE",sProperty); { eCC$&"
Utility.log(sProperty); G9g1hie@%
W;bu2ym&Q
d>;&9;)H
InputStream input = httpConnection.getInputStream(); =mA: ctu~v
//logResponseHead(httpConnection); ?\C"YG69T
}cT_qqw(f%
nF6q7
byte[] b = new byte[1024]; @u==x*{|
int nRead; Wu4Lxv]B4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q_-7i
{ i4^o59}8
nStartPos += fileAccessI.write(b,0,nRead); !r#?C9Sq
//if(nThreadID == 1) foJdu+^
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); (`y*V;o4
} =Umw$+fJr
O_Oj|'bBC
v) vkn/:
Utility.log("Thread " + nThreadID + " is over!"); TMYd47
bDownOver = true; `rf_7
//nPos = fileAccessI.write (b,0,nRead); z dO#0tN
} J_s>N
catch(Exception e){e.printStackTrace ();} (SKVuR%Jj
} [IK )
} 6Cn+e.j@
**}h&k&%2
<=f}8a.R3
//打印回应的头信息 `Od5Gh
public void logResponseHead(HttpURLConnection con) .A6(D$O k
{ OKoan$#sn
for(int i=1;;i++) r$2P;Cxj
{ ;qrB\j"
String header=con.getHeaderFieldKey(i); ;[fw]P n
if(header!=null) o7|eMe?<t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); } \ZaE~
Utility.log(header+" : "+con.getHeaderField(header)); *4V=z#
else dPhQ :sd>
break; O BN2 ) j
} 'nF2aD%A
} ^MVkZ{gtre
TYy.jFT-
V O3x~E
public void splitterStop() =5\|[NSK-
{ 5H ue7'LS
bStop = true; P>Ez'C
} %Ah^E$&n2
Zl*X?5u
xP[n
} B'fb^n<
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8O38#{[S
/* ,G2TVjz
**FileAccess.java "sG=wjcw^
*//文件访问(定位，写) m@^1JlH
package NetFox; |9B.mBoX
import java.io.*; ;72T|e
p>upA)W]
7k rUKYVo
public class FileAccessI implements Serializable{ >k'c'7/
V>b\[(=s
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L|,!?cSAT
RandomAccessFile oSavedFile; $g sxO!G
long nPos; v#!%GEg1r
sJDas,7>
-q*i_r:,
public FileAccessI() throws IOException e:5bzk!~
{ `b^Ru+(dM
this("",0); QDhOhGK
} T87m?a$
D ^x-^6^
H XmS|PX
public FileAccessI(String sName,long nPos) throws IOException Jl&-,Vjb
{ #H:7@
oSavedFile = new RandomAccessFile(sName,"rw"); M#8uv-L
this.nPos = nPos; zR{W?_cV
oSavedFile.seek(nPos); k<"oiCE
} v+X)Qmzf~
/@,j232
lb3]$Da
public synchronized int write(byte[] b,int nStart,int nLen) ;t|Ii8Ne
{ &MCbYph,
int n = -1; t$De/Uq
try{ pNKhc#-w
oSavedFile.write(b,nStart,nLen); ekWePL;rR2
n = nLen; <x<"n t
} 6e[VgN-s
catch(IOException e) d%o&+l#
{ u)~C;f)
e.printStackTrace (); |v$JCU3!A
} l\@)y4 +
]{ntt}3G,
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return n; 6x%h6<#xh*
} j'HZ\_
njWL U!
n\^Tq<] a
} /N&CaH\;^$
9R7A8
jbS\vyG
/* M)2VcDy
**SiteInfoBean.java t},/}b
*/ +Zaj,oEE
package NetFox; R5X.^u
34Kw!
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public class SiteInfoBean { ''0fF_P
k\NMy#]Zt
[< &oF
private String sSiteURL; //Site's URL !& z(:d
private String sFilePath; //Saved File's Path Y07ZB'K
private String sFileName; //Saved File's Name =5(>q5Z*
private int nSplitter; //Count of Splited Downloading File mqSQL}vR
F!]lU`z)=
jAm3HI
public SiteInfoBean() A m>cd;
{//nSplitter的缺省值为5 O8j_0
//default value of nSplitter is 5 nv~%#|v_W
this("","","",5); fvdU`*|n)
} F)'.g d
A^y|J`k|
8j=}u/T@F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $**r(HV
{ u (em&M
sSiteURL= sURL; &I (#Wy3
sFilePath = sPath; +i@y@<l:+
sFileName = sName; d;>#Sxf
this.nSplitter = nSpiltter; nh!a)]c[
j ~1B|,H
BA%pY|"Q
} ]y1OFKYv
>U]C/P[+
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public String getSSiteURL() \4-"L>
{ zhpt%7So
return sSiteURL; L.jh
} /p+>NZ"b
R}4So1
RHO(?8"_
public void setSSiteURL(String value) K%F,='P}
{ @M5#S7q";
sSiteURL = value; %Ntcvp)
} 9/ibWa\.
e0T34x'
OG~6L4"
public String getSFilePath() CJJzCVj
{ }DK7'K
return sFilePath; 7,lq}a8z
} hR Ue<0o:
fi$-;Gz
#>mr[
public void setSFilePath(String value) ]2\VweV
{ O2f-5Y$@
sFilePath = value; -< &D
} l33Pm/V2?
\V*xWS
Y<Fz)dQo
public String getSFileName() ;bLEL"x%
{ }9W4"e2)
return sFileName; ~R26
} /|eA9 ]
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.b6VQCS~9
public void setSFileName(String value) }`,t$NV`
{ kAC&S!n
sFileName = value; Ndcg/d
} ^]a#7/]o
bj"J'
d BJJZ^(
public int getNSplitter() R5 9S@MsuD
{ "G@g" gP
return nSplitter; }t%!9hr5D
} WUsKnf
8peDI7[|
(Yis:%c\!
public void setNSplitter(int nCount) ZObhF#Y9
{ 3 "Q=Vl"
nSplitter = nCount; X6mqi;+
} 8qEVOZjV&
} 45MLt5^|
,J{ei7TN
)l[M Q4vWW
/* $a"n1ou
**Utility.java |Clut~G
*/ nCj2N,mT
package NetFox; B&.FOO
U9A~9"O
d~:!#uWyFk
public class Utility { NX/;+{
r;Gi+Ca5
I9mvte
public Utility() V8HnUuz
{ \e'R@
}`v~I4i
L_+k12lm
} t$xY #:
0\@dYPa&C
//线程睡眠 ~D5\O6mU-
public static void sleep(int nSecond) I>[RqG
{ Rx);7j/5
try{ 2GWMlI
Thread.sleep(nSecond); u a~CEs
} hDcEGU_
catch(Exception e) CFqJ/''
{ L}}y'^(
e.printStackTrace (); :)_~w4&
} Z6_N$Z.A
} '`XX "_k3
c=L2%XPP
//日志 6C]1Q.f;
public static void log(String sMsg) zSSB>D
{ j^;I3_P
System.err.println(sMsg); 1Lg-.-V
} P~G1EK|4
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|/2y-[;:
public static void log(int sMsg) KTn}w:+B\
{ hlJq-*6'
System.err.println(sMsg); kIGbG;"_
} >OG:vw)E
} 72X0Tq 4
i2sN3it
v|Yh w
/* #DN0T' B
**TestMethod.java 1\g6)|R-+
*/ o4%y>d)
package NetFox; L dm?JrU
{.De4]ANh
Q<KvBgmT
public class TestMethod { Wt=|
y-j\zK
LNa$ X5`
public TestMethod() t\ 7~S&z
{ ///xx/weblogic60b2_win.exe +=mkCU
try{ |6(ZD^w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >zhO7,=,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); FI<q@HF
SiteFileFetch fileFetch = new SiteFileFetch(bean); L W;heO"
fileFetch.start(); +{/*z
} 5e}A@GyC
catch(Exception e){e.printStackTrace ();} 13+<Q \
>A<bBK#
}>'PT-
} L9@&2?k
Cz W:L&t
w1Ec_y{
public static void main(String[] args) $ KRI'4
{ %<\6TZr
new TestMethod(); 2Y>~k{AN%
} Udc=,yo3Qm
} (:";i&
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