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)); XdxSi"+
} >qC,IQ'
for(int i=0;i<nEndPos.length-1;i++) r`GA5}M
{ 5isqBu
nEndPos = nStartPos[i+1]; ?,0 a#lG
} *$yU|,
nEndPos[nEndPos.length-1] = nFileLength; 's_[#a;Vp
} @UCr`>
} p]erk
] g]^^
{f:%+h
//启动子线程 WYXh1_nyk
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '|rhm
for(int i=0;i<nStartPos.length;i++) ztb?4f q6)
{ ^'ac|+
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e'0BP,\f_}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), |Pj]sh[^Y
nStartPos,nEndPos,i); AD^Q`7K?uR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !$L~/<&0g
fileSplitterFetch.start(); 5l[&-:(Lh
} ,Vr-E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zqt{oN_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Sahz*f
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9qvKg`YSh
nEndPos = " + nFileLength); r:-,qy
// fileSplitterFetch[nPos.length-1].start(); %"CF-K@th
f'?FYBL
*9O@DF&*6
//等待子线程结束 <b#1L
//int count = 0; @Z2^smf
//是否结束while循环 o4F(X0
boolean breakWhile = false; ALXie86a8
7w51UmO
P}8cSX9
while(!bStop) ~ NZC0&
{ s_}q
write_nPos(); >7,?X_:A-1
Utility.sleep(500); 5-?*Boi>i
breakWhile = true; My<.^~
2D)B%nM[
'B yB1NL
for(int i=0;i<nStartPos.length;i++) It:,8
{ 1=z6m7@'-
if(!fileSplitterFetch.bDownOver) 4U>g0
{ ^bk:g}o
breakWhile = false; Fv$oXg/
break; :erfs}I
} V 0z`p"
} 7 F> a&r
if(breakWhile) K;j0cxl
break; 45A|KaVpg
gJBw6'Z
v+(-\T\i
//count++; "el}9OitC
//if(count>4) ~1:_wni
// siteStop(); ^2C \--=;
} yIYQ.-DkS+
MnTJFo"
R@~=z5X(Q
System.err.println("文件下载结束！"); .OcI.1H[
} >["X(%&w
catch(Exception e){e.printStackTrace ();} *b8AN3!
} K(r@JW
*3\Nj6
vR4omB{
//获得文件长度 7!/!a*zg
public long getFileSize() A9Icn>3?`(
{ F[KM0t!
int nFileLength = -1; `G:I|=#w
try{ *aW:Z6N
URL url = new URL(siteInfoBean.getSSiteURL()); +$$5Cv5#<&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )|wC 1J!L
httpConnection.setRequestProperty("User-Agent","NetFox"); $O_{cSKg7
ftxy]NLF
9";qR,
int responseCode=httpConnection.getResponseCode(); 21[=xboU
if(responseCode>=400) 7sq15oL
{ z-N N(G+
processErrorCode(responseCode); >!MRk[@ V-
return -2; //-2 represent access is error xSrjN
} 7:e5l19 uI
Y_nl9}&+C0
GB4^4Ajx
String sHeader; B&m6N,
W:>XXUU
yT|44 D2j
for(int i=1;;i++) N qS]dH61
{ r;_*.|AH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); GBY{O2!3u
//Utility.log(in.readLine()); w8cbhc
sHeader=httpConnection.getHeaderFieldKey(i); 089v; d 6
if(sHeader!=null) 'U-8w@\Z
{ _%G;^ b
if(sHeader.equals("Content-Length")) ~S\8 '
{ 5a&BgBO1M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); zl<D"eP
break; <:4b4Nl
} SZvp%hS0
} ipyc(u6Z5
else L)c]i'WZ
break; A|YiSwyy
} _*ar\A`
} XhUVDmeUMb
catch(IOException e){e.printStackTrace ();} XtqhK"f%
catch(Exception e){e.printStackTrace ();} OlP1Zd/l
q$PO.#
{F;"m&3Lt
Utility.log(nFileLength); {r%T_BfY
n0Qp:_2z
&v#pS!UOj
return nFileLength; XT?wCb41R
} >XxHp
@r=,: 'Mt
'<$*N
//保存下载信息（文件指针位置） :7~DiH:Q
private void write_nPos() mVEIHzk2b
{ kD(#LM<9s
try{ 6)c-s|#
output = new DataOutputStream(new FileOutputStream(tmpFile)); re4A5Ev$
output.writeInt(nStartPos.length); $18?Q+?3
for(int i=0;i<nStartPos.length;i++) \5}*;O@
{ _2hZGC%&E
// output.writeLong(nPos); @z^7*#vQv
output.writeLong(fileSplitterFetch.nStartPos); ~G1B}c]
output.writeLong(fileSplitterFetch.nEndPos); ~OWpk)Vq
} (8~D^N6Z
output.close(); a"l\_D'.K8
} yKy )%i
catch(IOException e){e.printStackTrace ();} k"|Fu
catch(Exception e){e.printStackTrace ();} 7AlL,&+
} qh+&Zx~
EQ.K+d*K][
P *&Cght>0
//读取保存的下载信息（文件指针位置） my0iE:
private void read_nPos() 9N<=,!;5~s
{ 4'TssRot@h
try{ ^B1$|C D,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >pp#>{}
int nCount = input.readInt(); NFF!g]QN
nStartPos = new long[nCount]; 7'#_uAQR
nEndPos = new long[nCount]; R3>c\mA
for(int i=0;i<nStartPos.length;i++) E 02Y,C
{ [^W +^3V
nStartPos = input.readLong(); N>CNgUyP
nEndPos = input.readLong(); :| !5d{8S8
} Sp2DpGs~
input.close(); 3 .K #,
} >.I9S{7
catch(IOException e){e.printStackTrace ();} uAV7T/'
catch(Exception e){e.printStackTrace ();} WrS>^\:
} ra2{8 x
zI\+]U'
U9K'O !i>
private void processErrorCode(int nErrorCode) t1NGs-S3
{ G;d3.ml/aZ
System.err.println("Error Code : " + nErrorCode); ~nb(e$?N
} m2P&DdN[
T0~~0G)k
@1xIph<z
//停止文件下载 z{&z
public void siteStop() qzEv!?)a
{ &;~?\>?I
bStop = true; i[ >U#5
for(int i=0;i<nStartPos.length;i++) ^C92R"*Qu
fileSplitterFetch.splitterStop(); fzA Fn$[
x6^Y&,y9kU
@AM11v\:
} e)N<r
} +z:>Nl
//负责部分文件的抓取 /4N?v. jf
**FileSplitterFetch.java +prUau*
*/ mkhWbzD'S
package NetFox; _8!x
0X4)=sJP
3y,2RernK
import java.io.*; @biU@[D
import java.net.*; -+M360
o)>iHzR</
f'w`<
public class FileSplitterFetch extends Thread { {> <1K6t
7XLqP
rxqSi0p
String sURL; //File URL .6C6ZUB;
long nStartPos; //File Snippet Start Position _]-4UA-
long nEndPos; //File Snippet End Position I9Uj3cL\
int nThreadID; //Thread's ID G&@dJ &B
boolean bDownOver = false; //Downing is over QBGjH^kL
boolean bStop = false; //Stop identical I~^Xw7
FileAccessI fileAccessI = null; //File Access interface !XM<`H/
uE<8L(*B
^B%c3U$o
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g"k4Z
{ 2r;h">
this.sURL = sURL; \.}ZvM$
this.nStartPos = nStart; u!&T}i:
this.nEndPos = nEnd; ~Uey'Xz
nThreadID = id; ijUu{PG`X
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tTF<DD}8
} <h;_:
{}rnn$HQe
\I-e{'h
public void run() tv`b##
{ l($8HAJ
while(nStartPos < nEndPos && !bStop) R\XS5HOE(
{ p2k`)=iX
"}#%h&,
\*'@F+
try{ Kn<+Au_]L
URL url = new URL(sURL); Z4c'1-lh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /qMnIo
httpConnection.setRequestProperty("User-Agent","NetFox"); y:^o._
String sProperty = "bytes="+nStartPos+"-"; /]_|uN)Q
httpConnection.setRequestProperty("RANGE",sProperty); j"hEs(t
Utility.log(sProperty); S3i p?9
wu><a!3`=o
/-i m g^^
InputStream input = httpConnection.getInputStream(); ivn2
//logResponseHead(httpConnection); x0jaTlU/
-*Rf [|Z
.@%L8_sMR
byte[] b = new byte[1024]; v|\#wrCT?
int nRead; fQ~TZ:UrU
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) TnKv)%VF
{ ?QzL#iO}h
nStartPos += fileAccessI.write(b,0,nRead); +/l@ou'
//if(nThreadID == 1) _hJdC|/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9P)!v.,T/
} g1}:;VG=
'RhS%l
Jwfb%Xge~
Utility.log("Thread " + nThreadID + " is over!"); %8h=_(X\7
bDownOver = true; <7SE|
//nPos = fileAccessI.write (b,0,nRead); I.G[|[. Do
} HA,8O[jon
catch(Exception e){e.printStackTrace ();} RgUQ:
} ~[dL:=?c
} }A,!|m4
KvEv0L<ky
`GW&*[.7
//打印回应的头信息 |59)6/i
public void logResponseHead(HttpURLConnection con) |JF,n~n
{ *4NY"EwjN
for(int i=1;;i++) gzn:]Y^
{ n|6G\99l+M
String header=con.getHeaderFieldKey(i); Du65>O
if(header!=null) 8h }a:/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @TD=or .&
Utility.log(header+" : "+con.getHeaderField(header)); O39
else s~2o<#
break; 7<*0fy5nn
} _z8"r&
} VFx[{Hy
li v=q
CHZ/@gc
public void splitterStop() <5}I6R;
{ H#D:'B j29
bStop = true; ,zr9*t
} 7M7Lj0Y)L
8/(}Wet
)^AZmUYZ
} \8!CKnfs
{U$XHG
R]e&JoY
/* Z37Dv;&ZD
**FileAccess.java - _8-i1?
*//文件访问(定位，写) *?d\Zcj85[
package NetFox; q~ ZUtF
import java.io.*; G4*&9Wo
0C>_aj
F-rhxJd
public class FileAccessI implements Serializable{ ]&"ii
1fMV$T==K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 #::+# G
RandomAccessFile oSavedFile; 6H: fg
long nPos; ,b -
Anu:
BYMdX J
public FileAccessI() throws IOException *#b e
{ @vyEN.K%mm
this("",0); `|>]P"9yp
} Hzm_o>^KC
Uq_lT,
iKV|~7nwO
public FileAccessI(String sName,long nPos) throws IOException YVa,?&i=N
{ XPqGv=CN
oSavedFile = new RandomAccessFile(sName,"rw"); =v?P7;T
this.nPos = nPos; VgIk'.
oSavedFile.seek(nPos); H`fJ<So?
} }|2A6^FH.
]r3/hDRDL@
hZ452W
public synchronized int write(byte[] b,int nStart,int nLen) K$,<<hl
{ mz%l4w?'
int n = -1; }q]*aADe
try{ 6q8}8;STTY
oSavedFile.write(b,nStart,nLen); IB|6\uKn
n = nLen; DJ<+" .v!
} .O'~s/h
catch(IOException e) aT IzfqCM
{ HVoPJ!K3
e.printStackTrace (); 4)D~S4{E5
} hBnUpYec
g[1>|Ax`'
]?H12xz
return n; -K?lhu
} ^*`#+*C
Jh=.}FXnjL
l$\B>u,>
} N,rd= m+
VnkhY
?xH{7)dO
/* wU!-sf;]y
**SiteInfoBean.java BXU0f%"8U
*/ 0+op|bdj
package NetFox; n@ba>m4{
G!sfp}qW
,LxZbo!
public class SiteInfoBean { -O?HfQ
CF','gPnc
BK4S$B
private String sSiteURL; //Site's URL d3q.i5']G
private String sFilePath; //Saved File's Path Qd YYWD
private String sFileName; //Saved File's Name ;@ixrj0u
private int nSplitter; //Count of Splited Downloading File rZpsC}C'
0j4n11#
A|1xK90^XT
public SiteInfoBean() KCbJ^Rln
{//nSplitter的缺省值为5 >'q]ypA1
//default value of nSplitter is 5 P HOngn
this("","","",5); { "Cu)AFy
} Hy\q{
`.O$RwC&7B
*9r(lmrfj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) kP[fhOpn
{ }"WovU{*s
sSiteURL= sURL; (_ :82@c
sFilePath = sPath; Zl&ED{k<
sFileName = sName; 2;"vF9WMm
this.nSplitter = nSpiltter; 8%u|[Si;
$`7Fk%#+e
ysK J=
} DFQ`(1Q
<";1[A%7<
0Yq_B+IC
public String getSSiteURL() eL"'-d+]
{ ~A5NseWCK
return sSiteURL; WgR%mm^
} @OT$* Qh
>Tl/3{V
"]G'^
public void setSSiteURL(String value) 2;>uP#1]
{ h%u!UHA
sSiteURL = value; OET/4(C
} ~D}fy
C}<e3BXc
D=z="p\
public String getSFilePath() ,.(:b82$
{ r`<e<C
return sFilePath; k6z ]-XG
} qS! Lt3+
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-f ~1Id
public void setSFilePath(String value) "#gKI/[qxq
{ klAlS%
sFilePath = value; +U J~/XV
} ga\s5
3=oxT6"k
fA<os+*9i
public String getSFileName() [Q8Wy/o Q
{ H'udxPF
return sFileName; qzORv
} Tim/7*vx
!:5'MI@
w@R"g%k-
public void setSFileName(String value) zfI{cMn'J
{ YI*H]V%w
sFileName = value; G$'UK
} hG~.Sc:G
>6&Rytcc]
q9{ h@y
public int getNSplitter() VByA6^JR
{ ;Dp*.YJ
return nSplitter; CfS;F
} ewn\'RLZ"@
Wf8@B#^{
q%q+2P>
public void setNSplitter(int nCount) g}Lm;gs!>
{ r ^*D8
nSplitter = nCount; /^jl||'H,:
} :oW 16m1`
} XSN=0N!GB
P8h|2,c%
JBHPI@Qt%
/* @>$qb|j
**Utility.java O86p]Lr
*/ `?[,1
package NetFox; q'y<UyT6
J9tV|0
K/Y"oQ2
public class Utility { ( 1
5c}loOq
o-&0_Zq_
public Utility() wsQuJrG
{ x|d?'
PWp=}f.y
tj*0Y-F~
} o[eZ"}~
9^H.[t
//线程睡眠 h,&{m*q&
public static void sleep(int nSecond) 4Ng:7C2
{ jHE^d<=O^
try{ z#`Qfvu6Hi
Thread.sleep(nSecond); tUOY`]0
} Nc[N 11?O
catch(Exception e) t OJyj49^a
{ %ueD3;V
e.printStackTrace (); }.8yKj^p
} Z Q*hrgQ
} e, 2/3jO
YZ:C9:S6X
//日志 m}D;=>2$
public static void log(String sMsg) Q;z!]hjBM
{ RS&BS;
System.err.println(sMsg); -e0[$v
} -~(d_
^C~R)M:C
FAc^[~E
public static void log(int sMsg) jK[*_V
{ '`<Fys&:
System.err.println(sMsg); #1*7eANfr
} O<|pw
} cl4_M{~
(`#z@,1
:t "_I
/* 9(!AKKrr;
**TestMethod.java hP.Km%C)0n
*/ s3@mk\?qMe
package NetFox; P4{~fh(
E8nj_^Z
]o=ON95ja
public class TestMethod { O x`K7$)
Sa@'?ApH
j+ L:Ao
public TestMethod() `x>6Wk1
{ ///xx/weblogic60b2_win.exe v{"yrC
try{ R:Ih#2R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Svo\+S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6yAZvX
SiteFileFetch fileFetch = new SiteFileFetch(bean); !kb:g]X
fileFetch.start(); +%klS `_
} ,g0t&jITo
catch(Exception e){e.printStackTrace ();} Np$&8v+en
o-l-Z|)7
FZ]+(Q"]:
} YXqYIG.G
iV#A-9
[\h?mlG?
public static void main(String[] args) PP!-*~F0Jr
{ AX1!<K
new TestMethod(); ?fC9)s
} d8 Jf3Mo
} f2M*]{N
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