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)); z/S,+!|z
} O7v]p
for(int i=0;i<nEndPos.length-1;i++) R8tF/dx>7
{ .Y!:x=e
nEndPos = nStartPos[i+1]; oAY_sg+
} _().t5<
nEndPos[nEndPos.length-1] = nFileLength; r:-WzH(Ms
} ; yyO0Ha
} tevQW
GJX4KA8J
Y&s2C%jT
//启动子线程 `|]e6Pb
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }'lNi^"XL
for(int i=0;i<nStartPos.length;i++) h2% J/69
{ uyFn}y62
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B s,as
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), NgHpIonC
nStartPos,nEndPos,i); ,>u=gA&}
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); VpSEVd:n
fileSplitterFetch.start(); CN/IH
} @;m$ua*|:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;`kWpM;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W}h|K:-S
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ;-Ss# &
nEndPos = " + nFileLength); 1~'_K9eE
// fileSplitterFetch[nPos.length-1].start(); |q_ !. a
('t kZt%8
>!}`%pk(
//等待子线程结束 -u|l}}bh
//int count = 0; t^.'>RwW|
//是否结束while循环 )Pli})
boolean breakWhile = false; }~Q5Y3]#~
J3G7zu8
_UkmYZ/
while(!bStop) =OYQM<q
{ W/r^ugDV
write_nPos(); t[EfOQ
Utility.sleep(500); &!jq!u$(
breakWhile = true; c&f y{}10
6^;^rUlm
Zn&k[?;Al
for(int i=0;i<nStartPos.length;i++) 2J<&rKCF
{ hmZvIy(
if(!fileSplitterFetch.bDownOver) yG&2UqX
{ iITp**l
breakWhile = false; C0fmmI0z~
break; YsP/p-
} bC~~5Cm
} Q2/.6O8
if(breakWhile) ~Fw<eY
break; ?+r!z
$b>}C= gt
-#?<05/C>
//count++; qzK("d
//if(count>4) m=TJDr-
// siteStop(); g_w&"=.jBq
} 9cd8=][
K)S;:MLG=
.0|=[|
System.err.println("文件下载结束！"); Q>8pP\ho
} [;KmT{I9
catch(Exception e){e.printStackTrace ();} st/n"HQ
} \cQ .|S
R#(G%66
%y"J8;U
//获得文件长度 vG Vd
public long getFileSize() 7 ({=*
{ xNpg{cQ=
int nFileLength = -1; >fzwFNdo
try{ sG,+
URL url = new URL(siteInfoBean.getSSiteURL()); Y)XvlfJ,h?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >t3'_cBC!
httpConnection.setRequestProperty("User-Agent","NetFox"); g:<?
)NT5yF,m
n.hElgkUOr
int responseCode=httpConnection.getResponseCode(); W#XG;
if(responseCode>=400) \M(*=5
{ u@=?#a$$
processErrorCode(responseCode); 9vI]LfP
return -2; //-2 represent access is error = .oHnMX2M
} *Oo &}oAj
Dag`>|my
6T+
String sHeader; 4/*H.Fl
~p*1:ij
],lV}Mlg*
for(int i=1;;i++) |d7$*7TvV
{ G> \Tbx
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LdTdQ,s<
//Utility.log(in.readLine()); wAYB RY[
sHeader=httpConnection.getHeaderFieldKey(i); q0O&UE)6Y
if(sHeader!=null) lKKERO5+
{ ZA\/{Fw
if(sHeader.equals("Content-Length")) zgKY4R{V
{ RFko>d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "Xn%at4
break; $/_qE
} 0a2@b"l
} .Q>!B?)
else &ZJgQ-Pc(m
break; ^#e~g/
} xx8U$,Ng
} :reTJQwr
catch(IOException e){e.printStackTrace ();} Z$'IBv
catch(Exception e){e.printStackTrace ();} 8Fq_i-u
K:5eek
?KWj}|%
Utility.log(nFileLength); nWWM2v
~ 3T,&?r
fgF;&(b
return nFileLength; $'"8QOnJ?k
} SKXD^OH
F}X0',
7m1KR#j
//保存下载信息（文件指针位置） Kt/)pc
private void write_nPos() AQ{zx1^2>K
{ 4TRG.$2[
try{ {CUk1+
output = new DataOutputStream(new FileOutputStream(tmpFile)); UUtbD&\
output.writeInt(nStartPos.length); 4]&<?"LSK
for(int i=0;i<nStartPos.length;i++) cHD%{xlb
{ "uD=KlA
// output.writeLong(nPos); ZR3nK0
output.writeLong(fileSplitterFetch.nStartPos); lDc;__}Ws
output.writeLong(fileSplitterFetch.nEndPos); . (`3JQ2s
} lCb+{OB
output.close(); y79qwM.
} c-CYdi@
catch(IOException e){e.printStackTrace ();} KN[d!}W:
catch(Exception e){e.printStackTrace ();} 6C-YyI#s#
} !3}deY8;#
>HTbegi
IcF@F>>
//读取保存的下载信息（文件指针位置） 85]SC$
private void read_nPos() ;IZ?19Q
{ g]$ 4~"|.
try{ <{ru|-9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K5"sj|d&
int nCount = input.readInt(); d"THt}
nStartPos = new long[nCount]; Q9>U1]\
nEndPos = new long[nCount]; (f1M'w/OD
for(int i=0;i<nStartPos.length;i++) q<{NO/Mm
{ O`W%Tr
nStartPos = input.readLong(); k%Vv?{g
nEndPos = input.readLong(); g-)mav
} cT'w=
input.close(); fCUT[d+H
} [Ot,q/hBJ
catch(IOException e){e.printStackTrace ();} I6w~H?ul@*
catch(Exception e){e.printStackTrace ();} B)=~8wsI:Z
} ($!KzxF3
rVryt<2:@r
e!x6bR9EZ
private void processErrorCode(int nErrorCode) {aj/HFLNY
{ %c/^_.
System.err.println("Error Code : " + nErrorCode); %:u[MBe,
} )]Ti>RO7
s#-eN)1R
t#~?{i@m
//停止文件下载 F@vbSFv)/
public void siteStop() Cmd329AH
{ y] V1b{9p
bStop = true; 'K@0Wp
for(int i=0;i<nStartPos.length;i++) _sMs}?^
fileSplitterFetch.splitterStop(); r%=[},JQ
[ygF0-3ND
+m$5a YX
} #V_GOy1-
} mJ
//负责部分文件的抓取 /iM$Tb5
**FileSplitterFetch.java 79Bg]~}Z
*/ ?y7w}W
package NetFox; Of7+/UV
e<\<,)9@/
RA1yr+)
import java.io.*; tIZ~^*'
import java.net.*; :@. ;
'jaoO9KY K
>|udWd^$3
public class FileSplitterFetch extends Thread { T] | d5E
oRY!\ADR
jX */piSq
String sURL; //File URL /oP^'""@je
long nStartPos; //File Snippet Start Position J)x3\[}Ye
long nEndPos; //File Snippet End Position c{3rl;Cs
int nThreadID; //Thread's ID s:|M].
boolean bDownOver = false; //Downing is over y!Cc?$]_Y
boolean bStop = false; //Stop identical ~!:0iFE&H
FileAccessI fileAccessI = null; //File Access interface \L]|-f(4
<$Yi]ty
f} K`Jm_}?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException l I-p_K
{ (.X]F_*sc
this.sURL = sURL; =nxKttmU0
this.nStartPos = nStart; tJD] (F
this.nEndPos = nEnd; *i%quMv
nThreadID = id; Jh@_9/?
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tS?lB05TOR
} 5vOCCW
}STYG`
l[Z)@bC1
public void run() $&{IKP)u
{ 80hme+e
while(nStartPos < nEndPos && !bStop) tL(BpL'
{ T1 MY X
?b:_AO&
Faac]5u:*
try{ v,1F--v
URL url = new URL(sURL); $|<m9CW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >S#ul?
httpConnection.setRequestProperty("User-Agent","NetFox"); tFh|V pB
String sProperty = "bytes="+nStartPos+"-"; I$jvXl=$
httpConnection.setRequestProperty("RANGE",sProperty); ijYvqZ_
Utility.log(sProperty); .ER98
N}Vn;29
_m'ysCjA
InputStream input = httpConnection.getInputStream(); H{zPft
//logResponseHead(httpConnection); :7b-$fm
;#QhQx
<Oz66bTze
byte[] b = new byte[1024]; W|R-J
int nRead; GESXc$E8
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) *HlDS22
{ 96ZdM=
nStartPos += fileAccessI.write(b,0,nRead); ltA/
//if(nThreadID == 1) PZOKrW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a(x?fa[D
} "4 k-dj
?]!vRmZ;
><Z'D
Utility.log("Thread " + nThreadID + " is over!"); %xlpB75N4N
bDownOver = true; 1y[B[\
//nPos = fileAccessI.write (b,0,nRead); U[8{_h<#
} fE25(wCz7
catch(Exception e){e.printStackTrace ();} Yp5L+~J[
} =3'(A14C=
} 6?gi_3g
uP|FJLY
zhsx&
//打印回应的头信息 `deYi2z
public void logResponseHead(HttpURLConnection con) |f' 8p8J
{ sdr.u
for(int i=1;;i++) Xr_pgW|
{ +_mr
String header=con.getHeaderFieldKey(i); HeIS;gfUY
if(header!=null) G$=-,6kZO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y-+G wa3
Utility.log(header+" : "+con.getHeaderField(header)); @$U e$
else vDE |sT
break; Z)9R9s
} %e=!nRc
} T\sNtdF`:
(B#(Z=
C0m\SNR
public void splitterStop() =ApY9`
{ Q7a(P
bStop = true; k0ItG?Cv
} *\ECf.7jz
8wFn}lw&
P6Xp<^%E
} w|Qd`
+/cgw,
Gp|JU Fo
/* gGfq6{9g
**FileAccess.java =/Juh7[C
*//文件访问(定位，写) uqZ3Hyb
package NetFox; ,2zKQ2z
import java.io.*; m&El)
3|eUy_d3
r+\/G{+=}
public class FileAccessI implements Serializable{ JvJ;bFXD
Q[_Ni15
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J/kH%_ >Ir
RandomAccessFile oSavedFile; dR[o|r
long nPos; ^k72{ 3N(
'JZ_
c@OP5L>{
public FileAccessI() throws IOException 8 /m3+5
{ ^H=o3#P~L
this("",0); hyu}}0:
} _*`q(dYcf
>q9{
0k1MKzi Q
public FileAccessI(String sName,long nPos) throws IOException MSYN1
{ $u5.!{Wq?
oSavedFile = new RandomAccessFile(sName,"rw"); ,nYZxYLf+
this.nPos = nPos; cU | _
oSavedFile.seek(nPos); !5.v'K'
} ;=p;v .l
WZ*&@|w
Sx&mv.?X
public synchronized int write(byte[] b,int nStart,int nLen) :ICr\FY$
{ gb-tNhJa@b
int n = -1; sU%"azc
try{ }td6fj_{
oSavedFile.write(b,nStart,nLen); d*9j77C]
n = nLen; b|wWHNEdb,
} o*_g$
catch(IOException e) 3yMt1 fy
{ 2np-Fc{S
e.printStackTrace (); <^sAY P|
} l $Zs~@N
J/7u7_
M?hFCt3Y
return n; <2)v9c
} Xz* tbW#
5KaSWw/
9|a)sb7/
} $4h04_"
~UW{)]_jox
Q9q9<J7j$
/* FB!z#Eim
**SiteInfoBean.java va+m9R0
*/ =n)#!i
package NetFox; rgn|24x
{~1M
?,V;f2c
public class SiteInfoBean { gTD%4V
O3}P07
!vrnoFVu
private String sSiteURL; //Site's URL VY{,x;O`
private String sFilePath; //Saved File's Path ,whM22Af~{
private String sFileName; //Saved File's Name %w@ig~vD'
private int nSplitter; //Count of Splited Downloading File ASM1Y]'Z
.lG+a!)
_!;\R7]
public SiteInfoBean() %\_h7:
{//nSplitter的缺省值为5 gyg|Tno
//default value of nSplitter is 5 4sQ~&@[Q+
this("","","",5); Bf(Mot^
} 04[)qPPS
dcR6KG8
y|LXDq4Wj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6d(b'S^
{ Y?e3Bx7*b
sSiteURL= sURL; bZnDd
sFilePath = sPath; $"(3MnR
sFileName = sName; EKJH_!%
this.nSplitter = nSpiltter; IjgBa-o/V
MIJ%_=sm4:
8ZzU^x
} >:fJhF@
]q37Hj
*<;&>w8
public String getSSiteURL() [L)V(o)v
{ Z%A<#%
return sSiteURL; @Zh8 QI+
} Y~x`6
Wd1 IX^7C%
tUn&z?7bF
public void setSSiteURL(String value) 5 u"nxT
{ v.]'%+::#
sSiteURL = value; iiQ||P}5
} ^$6bs64FSm
bsD'\
#d$d&W~gE
public String getSFilePath() F^[M
{ ^>t-v
return sFilePath; YU*46 hA1B
} =7H.F:BBG
64;oB_
}% FDm@+
public void setSFilePath(String value) bmSpbX\
{ <w%Yq?^
sFilePath = value; sCL/pb]
} Yoj~|qL
>^sz5d+X
aB7d(
public String getSFileName() _TV2)
{ upZYv~Sa
return sFileName; / *Ou$
} +q4W0
U_.n=d~B
k_-vT
public void setSFileName(String value) 'aLPTVM^
{ 01UqDdoj
sFileName = value; oR4fK td
} iRkOH]+K
DKf}47y
t=AE7
public int getNSplitter() |~Htj4K/
{ LAOdH/*:
return nSplitter; z2"2tFK
} tOu90gu
/5a$@%
U+I3P
public void setNSplitter(int nCount) ^Osd/g
{ $#g#[/
nSplitter = nCount; qYQUr8{
} xF2f/y
} N}eU.#L
Y*h`),
Q'>_59
/* D>,$c
**Utility.java DtI%-I.
*/ P6.)P|n7=
package NetFox; 1e+h9|hGYw
0Ax>gj-`
Hz8Jgp
public class Utility { rjhs?
'Y,+D`&i)
)< X=z
public Utility() PxdJOtI"
{ ft*G*.0kO
tF{{cd
D>!v_v6
} 'd~, o[x
2_B;
//线程睡眠 PprQq_j
public static void sleep(int nSecond) /zDSlj<c
{ YA1{-7'Q
try{ ]JhDRJ\
Thread.sleep(nSecond); 7%~VOB
} Bh.6:9{
catch(Exception e) WVBE>TB
{ 64IeCAMVo
e.printStackTrace (); }V93~>
} XPR:_
} [:/7OM
/cn/[O9
//日志 b[QCM/
public static void log(String sMsg) u0(hVK`":
{ n?7hp%}
System.err.println(sMsg); U?+30{hb
} 'Sb6 w+
7.F& {:@_
W! 5Blo
public static void log(int sMsg) )%nt61P\W
{ hx2!YNx !
System.err.println(sMsg); Wr}a\}R
} +9=p*3cnp
} 3XYIbXnk
PLY-,Q&'
10QNV=yK7s
/* */fs.G:P
**TestMethod.java v/4X[6(
*/ E Ni%ge'":
package NetFox; ijR*5#5h
bb0{-T)1
ZJ{+_ax0K
public class TestMethod { 2t Z\{=
7J)Hwl
%\s#e
public TestMethod() tjc5>T[Es8
{ ///xx/weblogic60b2_win.exe 0B!mEg
try{ ;Wp`th!F
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); f;qKrw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); hVQ+ J!qD
SiteFileFetch fileFetch = new SiteFileFetch(bean); 55jY` b.
fileFetch.start(); !:!@dC%8_
} ~O7cUsAi'
catch(Exception e){e.printStackTrace ();} da7x 1n$D
]pucv!
jv?aB
} k6 h^
1v8:,!C
dBi3ZCAF
public static void main(String[] args) S+bWD7
{ CUTEp/+
new TestMethod(); } cH"lppX
} .k?hb]2N
} t]YLt ,
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