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)); tpK4 gjf
} m/Z_HER^
for(int i=0;i<nEndPos.length-1;i++) "PtH F`mo
{ Jl ?Q}SB
nEndPos = nStartPos[i+1]; 3zHiu*2/!
} *?&O8SSBH
nEndPos[nEndPos.length-1] = nFileLength; KIJ[ cIw
} o#6}?g.
} jXZNr
Z.JTq~`I
KZNyp%q
//启动子线程 /d'u1FnA=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s&</zU'
for(int i=0;i<nStartPos.length;i++) k#[s)Ja?s
{ !o!04_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gs>cx]>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~!kbB4`WK
nStartPos,nEndPos,i); =p6xc}N
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mNKa~E
fileSplitterFetch.start(); RoZV6U~
} 8{u01\0}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +dv@N3GV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {%Sww:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?|dz"=y
nEndPos = " + nFileLength); h6t>yC\
// fileSplitterFetch[nPos.length-1].start(); v2V1&-
?#m5$CFp
.YRSd
//等待子线程结束 (6{ VMQ
//int count = 0; P+UK@~D+G
//是否结束while循环 wQc w#
boolean breakWhile = false; y[rLk
9A!qg<
3>6o=7/PU
while(!bStop) .@Cshj
{ b.;W|$.
write_nPos(); 6wgOmyJx
Utility.sleep(500); Y)`+u#` R
breakWhile = true; ,}0pK\Y>$
.bGeZwvf:G
(Q+3aEUE
for(int i=0;i<nStartPos.length;i++) <9~qAq7^
{ aJ5R0Y,
if(!fileSplitterFetch.bDownOver) %ZK}y{u\
{ =qRVKz
breakWhile = false; X'm2uOEj
break; x?IT#ty
} G w[&P%
} U9w*x/Swb
if(breakWhile) Cn<x
break; ?x97q3I+]
[6|vx},N
NL 37Y{b
//count++; `upNP/,
//if(count>4) ks}o9[D3
// siteStop(); \bfHGo=
} 5hAg*zJb5o
./d (@@
?x@khzk
System.err.println("文件下载结束！"); !MC Wt
} G.}yNjL8
catch(Exception e){e.printStackTrace ();} @w0[5ZAj
} (EX
"^H+A-R[
zjmc>++<t
//获得文件长度 L;"<8\vWB
public long getFileSize() jo^*R'}
{ ?6dtvz;K+?
int nFileLength = -1; fVM%.`
try{ CvN~
URL url = new URL(siteInfoBean.getSSiteURL()); XHr{\/4V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :$j~;)2
httpConnection.setRequestProperty("User-Agent","NetFox"); *u}):8=&R
^4"_I
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int responseCode=httpConnection.getResponseCode(); EB#z\
if(responseCode>=400) yl}Hr*
{ 7@FB^[H:y
processErrorCode(responseCode); Ogb_WO;)
return -2; //-2 represent access is error ( nh!tC
} A SSoKrFL
C N"c
G\Me%{b#
String sHeader; P(`IY+
JI&>w-~D
ezn>3?S
for(int i=1;;i++) Fv9Z'#t
{ }5k"aCno
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $sJn: 8z
//Utility.log(in.readLine()); ,>$#e1!J
sHeader=httpConnection.getHeaderFieldKey(i); md0=6< }P
if(sHeader!=null) VV
{ dZW:Cf 9K
if(sHeader.equals("Content-Length")) n>HNpy
{ Vr*t~M>
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gJ])A7O
break; +K?h]v]%
} p,Z6/e[SI
} bY>Ug{O;
else S;])Nt'X'
break; /dfZ>k8
} }DSz_^
} ^!9b#Ja
catch(IOException e){e.printStackTrace ();} o$-Phl
catch(Exception e){e.printStackTrace ();} UZ1lI>
MWl@smRh
/a q%l]hQ@
Utility.log(nFileLength); P}5aN_v\
*%O1d.,
-4Xr5j%o
return nFileLength; lcr=^
} #xc[)Y,W
yhIg)/?L
v%1#y5
//保存下载信息（文件指针位置） MiC&av
private void write_nPos() L4NC-
{ a-3~HH
try{ '/j`j>'!^
output = new DataOutputStream(new FileOutputStream(tmpFile)); G>,rf ]N
output.writeInt(nStartPos.length); 3t,SXI@
for(int i=0;i<nStartPos.length;i++) R:e:B7O~0
{ oI>;O#
// output.writeLong(nPos); 0XYxMN)
output.writeLong(fileSplitterFetch.nStartPos); pQp}HD!-
output.writeLong(fileSplitterFetch.nEndPos); |"mb59X
} gor6c3i
output.close(); ' 9,}N:p
} @.})nU
catch(IOException e){e.printStackTrace ();} !-QKh aY
catch(Exception e){e.printStackTrace ();} Rwr0$_A
} ,y0kzwPR1
;#;X@BhS
V><P`
//读取保存的下载信息（文件指针位置） y?rsfIth`
private void read_nPos() s#Le`pGoW
{ 6?_Uow}
try{ 0`x<sjG\q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ecHy. 7H
int nCount = input.readInt(); b,cvQD
nStartPos = new long[nCount]; L$b9|j7
nEndPos = new long[nCount]; !O5UE
for(int i=0;i<nStartPos.length;i++) &EQov9P7
{ _uBf.Qfs
nStartPos = input.readLong(); !yxb<
nEndPos = input.readLong(); E`i;9e'S
} "-hgeQX
input.close(); tly:$;K
} *) wp
catch(IOException e){e.printStackTrace ();} b#P8Je`;9
catch(Exception e){e.printStackTrace ();} `mMD e
} [p<L*3<
GL/\uq
y|@^0]}%<
private void processErrorCode(int nErrorCode) H(pOR<`
{ 0trFLX
System.err.println("Error Code : " + nErrorCode); &v:iC u^|
} UpgOU.
nyIb8=f
n\ IVpgP
//停止文件下载 =v_ju;C=
public void siteStop() T1x$v,)8x
{ F;zmq%rK
bStop = true; tHGK<rb
for(int i=0;i<nStartPos.length;i++) =3}+f-6"'
fileSplitterFetch.splitterStop(); Dk4Wj"LS
ZK13[_@9
Z?GC+hG`
} hP7nt
} <q!{<(:
//负责部分文件的抓取 >uQ!B/C!
**FileSplitterFetch.java 7mu%|!
*/ {_ #
package NetFox; 74KFsir@
)X@(>b{
wHAh6lm
import java.io.*; ]Rw,5\0
import java.net.*; k<:!^_3H
D`LwW` 9
b~\![HoCMM
public class FileSplitterFetch extends Thread { _rajm J
:dK%=j*ZK
C6Kz6_DQZ
String sURL; //File URL N8KHNTb-M
long nStartPos; //File Snippet Start Position wo*/{KFvh
long nEndPos; //File Snippet End Position @50Js3R1q
int nThreadID; //Thread's ID v.\&gn(
boolean bDownOver = false; //Downing is over ]$z~;\T
boolean bStop = false; //Stop identical o&>0 pc
FileAccessI fileAccessI = null; //File Access interface KR{kn[2|Q
] $%{nj<
?56Zw"89
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \O^= Z{3y
{ bT8BJY%+
this.sURL = sURL; o77HRX
this.nStartPos = nStart; 9J>DLvl;
this.nEndPos = nEnd; "['YMhu_
nThreadID = id; 1s*I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ftK.jj1:
} }$b/g
?"L>jr(
>s1HQSe66
public void run() Tp9LBF
{ B[k"xs
while(nStartPos < nEndPos && !bStop) D$j`+`
{ z\;kjI
(V |P6C
/]YK:7*98
try{ p,xM7V"O)
URL url = new URL(sURL); jSddjs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oXGf#>keg
httpConnection.setRequestProperty("User-Agent","NetFox"); $+?6U
String sProperty = "bytes="+nStartPos+"-"; 0|HhA,u
httpConnection.setRequestProperty("RANGE",sProperty); D]4?UL
Utility.log(sProperty); #M_QSD}&
<,LeFy\zW
{B[i|(xQx
InputStream input = httpConnection.getInputStream(); Vv zd>yII
//logResponseHead(httpConnection); 6H3_qx
g:O.$
P{);$e+b~
byte[] b = new byte[1024]; yLI=&7/e@
int nRead; d{YhKf#~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) IQH;`+
{ 5xRh'Jkyb
nStartPos += fileAccessI.write(b,0,nRead); wl!'Bck=
//if(nThreadID == 1) EK#w: "
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FL`. (,
} RRV&!<l@$
;E*ozKpm
J,E&Uz95%
Utility.log("Thread " + nThreadID + " is over!"); FCI38?`%
bDownOver = true; u<+;]8[o
//nPos = fileAccessI.write (b,0,nRead); >;HXH^q
} (/uL6W d0
catch(Exception e){e.printStackTrace ();} BURiLEYZl
} Z-:$)0f
} u0i @.
s n?
4I,HvP
//打印回应的头信息 (L~3nN;rr
public void logResponseHead(HttpURLConnection con) NeNKOW#X
{ X_=oJi|:
for(int i=1;;i++) +[z(N
{ jP+4'O!s[
String header=con.getHeaderFieldKey(i); ;&[0 h)
if(header!=null) "b2Mk-qP
//responseHeaders.put(header,httpConnection.getHeaderField(header)); gg6&Fzp
Utility.log(header+" : "+con.getHeaderField(header)); Qy15TJ
else q/]tJ{FI
break; -"(e*&TJ#
} X5)>yM^N`
} OY?uqP}c
@ cv`}k
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public void splitterStop() 7\jH?Zi
{ J\2F%kBej?
bStop = true; TzPVO>s
} N\H(AzMw
Z3[,Xw
D@\97t+
} o6{XT.z5qx
c5Offnq'1
{\ .2h
/* 2b!b-
**FileAccess.java ZW,PZ<
*//文件访问(定位，写) z?V> ST
package NetFox; 4N*^%
import java.io.*; D:){T>
+!w?g/dV
1)k))w9
public class FileAccessI implements Serializable{ G|H\(3hHLZ
Y/{Z`}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6#dx%TC
RandomAccessFile oSavedFile; .}j@(D
long nPos; \QHM7C T
jQf1h|e
\*_qP*vq@
public FileAccessI() throws IOException sba0Q[IY
{ 0E++
this("",0); KX*e2 /0
} LZ^sc
zu*h9}
d'DS7F(c{
public FileAccessI(String sName,long nPos) throws IOException I|BLAm6j
{ Ph-3,cC
oSavedFile = new RandomAccessFile(sName,"rw"); }_u)3X.O
this.nPos = nPos; 8whjPn0
oSavedFile.seek(nPos); 7_A(1Lx/l7
} :%s9<g;-h_
GT'%HmQI
A(<- U|
public synchronized int write(byte[] b,int nStart,int nLen) WukCE
{ s;$ eq);
int n = -1; .i`+}@iA
try{ u*H2kn[DU
oSavedFile.write(b,nStart,nLen); `t#C0
n = nLen; k%c ?$n"
} z#O{rwnl
catch(IOException e) ;9b?[G
{ 3):7mE(
e.printStackTrace (); I8?egDkk
} 6:QJ@j\
GY0<\-
mb?yG:L=0b
return n; HaLEQ73
} #r0A<+t{T
[_b10Z'{
SkN^ytKE
} E6BW&Xp
vUj7rDT|
!$Mv)c/_u
/* J2yq|n?2gq
**SiteInfoBean.java Cvi-4
*/ @-Gf+*GZys
package NetFox; a#KxjVM
,{YC|uB
P`RM"'Om
public class SiteInfoBean { GAPZt4Z2
mo<g'|0
hZ$* sf
private String sSiteURL; //Site's URL 69rVW~Z
private String sFilePath; //Saved File's Path $8X?|fV)
private String sFileName; //Saved File's Name vChkSY([
private int nSplitter; //Count of Splited Downloading File \b~zyt6-
-!7QH'
VSM%<-iQ
public SiteInfoBean() jj.)$|&#`
{//nSplitter的缺省值为5 d0|Q1R+3
//default value of nSplitter is 5 4}96|2L5
this("","","",5); x+%lNR
} %_}#IS1
e@@kTny(
5>$*#0%"}
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) XIf,#9
{ $D8KEkW
sSiteURL= sURL; b>;5#OQfn
sFilePath = sPath; l--xq^,`o]
sFileName = sName; SyTcp?H
this.nSplitter = nSpiltter; r+\it&cW+
/V:%}Z
KvC:(Vqj
} %!LrC!6P4
]ujH7T
4AUY8Pxp
public String getSSiteURL() FL0[V,
{ *}3~8fu{
return sSiteURL; 3Qn! `
} babDLaC@
?T?%x(]I
Xdw%Hw
public void setSSiteURL(String value) YjLPW@
{ ^> ZQ:xs@(
sSiteURL = value; qo4AQ}0 <
} /|BzpIfpN
b-%7@j
3-tp94`8}t
public String getSFilePath() J:pnmZ`X
{ >P+V!-%#
return sFilePath; `7+?1z
} 67Ge}6*2pd
hF!yp7l;
p8o%H-Xk
public void setSFilePath(String value) }?8KFe7U
{ R3%T}^;f
sFilePath = value; ,O $F`0>9A
} \fh.D/@
]TqcV8Q~
h.=YAcR0D
public String getSFileName() 9sJbz=o]r
{ 2{#*z%|z
return sFileName; m6aoh^I
} -mcLT@
Zna }h{
LBw,tP
public void setSFileName(String value) ml\7JW6Rx
{ In:h%4>
sFileName = value; $kkdB,y
} F1gDeLmJ
kax9RHvku
<&b ~(f
public int getNSplitter() V|<qO-#.
{ ';zLh
return nSplitter; ?Q:se
} /vSFQ}W
vqv(KsD+::
>PL/>
public void setNSplitter(int nCount) `hI1
{ st'Y j
nSplitter = nCount; ZVgR7+`]#
} 5as';1^P&*
} <N+l"Re#]
~"+[VE5
RSzp-sKB
/* E8#y9q
**Utility.java j3sUZg|d
*/ q>!T*BQ
package NetFox; m <aMb
,Lox?}t
uqX"^dn4u
public class Utility { <f8@Qij
Z37Z
=@w};e#D
public Utility() A3!NEFBK
{ iTqv=
aN%t>*?Xa
2ggW4`"c
} /.7x[Yc
pl|<g9
//线程睡眠 mS!/>.1[
public static void sleep(int nSecond) +~8/7V22
{ YWd:Ok0
try{ D;d'ss;
Thread.sleep(nSecond); f5mk\^
} gd#
catch(Exception e) %Xkynso~
{ |'Ve75 W6u
e.printStackTrace (); -V_e=Y<J/
} >L[,.}(9
} QF!K$?EU[
*l_1T4]S
//日志 2Np9*[C
public static void log(String sMsg) 0z.`
{ x/bO;9E%U4
System.err.println(sMsg); AUzJ:([V
} q'",70"\
^=.|\ YM
LvhF@%(9J
public static void log(int sMsg) 2*%0m^#^6
{ @fbvu_-].
System.err.println(sMsg); r{p?aG
} BYNOgB1
} )1lYfJ
0`,a@Q4
pr@8PD2%
/* ''v_8sv
**TestMethod.java o6Vc}jRH
*/ )<-kS
package NetFox; 'Kp|\Tr
@2kt6 W
:m@(S6T m
public class TestMethod { LW ntZ.
~cU,3g
3Mr)oM<Q
public TestMethod() v\$XhOK
{ ///xx/weblogic60b2_win.exe |hOqz2|
try{ 2$\Du9+
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z+I[
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 'X@j
SiteFileFetch fileFetch = new SiteFileFetch(bean); PM o>J|^
fileFetch.start(); X B65,l
} }SUe 4r&4}
catch(Exception e){e.printStackTrace ();} wyvs#T
/!jn$4fd:
9QWS[E4
} ;t[<!
+#'exgGU^[
a+r0@eFLc
public static void main(String[] args) ;h0?o*i_
{ PNg,bcl
new TestMethod(); GS<,adD
} =Lp0i9c
} ^J@Y?CQl\
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