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)); 6("bdx;!
} #|(>UM\
for(int i=0;i<nEndPos.length-1;i++) Z : xb8]y
{ G'}N?8s1
nEndPos = nStartPos[i+1]; Pp8G2|bz
} I;E?;i
nEndPos[nEndPos.length-1] = nFileLength; d_pIB@J
} .*9u_2<
} ,"gPd!HD(
eIF6f& F
>lQa"F=
//启动子线程 D]*|Zmr+}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 5VOw}{Pt
for(int i=0;i<nStartPos.length;i++) VY8cy2
{ Cm%I/4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n&P~<2^M#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %~M*<pN
nStartPos,nEndPos,i); :*|Ua%L_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n YUFRV$
fileSplitterFetch.start(); <&) hg:
} Nr$78] o9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N*&T)a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GwP!:p|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", c?_7e9}2
nEndPos = " + nFileLength); B'(zhjV
// fileSplitterFetch[nPos.length-1].start(); =Hd#"9-
sK+uwt
_Y&.Nw
//等待子线程结束 (2>q
//int count = 0; F09%f"9
//是否结束while循环 Xy K,
boolean breakWhile = false; kw2yb
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)LKJfoo PY
while(!bStop) 1~~GF_l?
{ a$Ud"
write_nPos(); ?K:\WW
Utility.sleep(500); 0ElEaH1z
breakWhile = true; yUo8-OaL7
G93V=Bk=
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for(int i=0;i<nStartPos.length;i++) ^c}3o|1m(
{ ?uL-qsU
if(!fileSplitterFetch.bDownOver) H.;}%id
{ 3ddw'b'aQ
breakWhile = false; ~>9G\/u j
break; bK0(c1*a[e
} 9,_~qWw
} 25vjn 1$sW
if(breakWhile) 985h]KQ
break; v.C
RDHK'PGA
H{5, -x
//count++; pA_u;*
//if(count>4) ~?aFc)
// siteStop(); gAztdAsLM
} P,)D0i
q|]CA
W =Bw*o-
System.err.println("文件下载结束！"); l\V1c90m
} BRY/[QRqZ
catch(Exception e){e.printStackTrace ();} -o"b$[sf=Z
} tR<#CCtRp'
0vSPeZ
juF=ZW%i
//获得文件长度 5&EBUl}
public long getFileSize() d-Z2-89K
{ +VW8{=$
int nFileLength = -1; jG{?>^
try{ xsRkO9x
URL url = new URL(siteInfoBean.getSSiteURL()); Lm`-q(!7w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q\i&ERr
httpConnection.setRequestProperty("User-Agent","NetFox"); 1I69O6"
Ty{ SZUJ
Q) aZ0 Pt
int responseCode=httpConnection.getResponseCode(); ,|VLOY^
if(responseCode>=400) EU:N9oT
{ ub>:dNBN
processErrorCode(responseCode); >/4[OPB0R
return -2; //-2 represent access is error #V/{DPz
} 5ta;CG
'do2n/
Uq'W<.v5
String sHeader; z;9D[ME#1
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6U8esPs,
for(int i=1;;i++) IZ>l
{ k -R"e
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ue7D' UZL>
//Utility.log(in.readLine()); qP;1LAX
sHeader=httpConnection.getHeaderFieldKey(i); "DvZCf[}
if(sHeader!=null) Lks+FW
{ v07A3oj
if(sHeader.equals("Content-Length")) pl@K"PRE
{ G?,3Zn0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %Ul,9qG+
break; .J @mpJdY
} ~PyS;L}
} #U%HGTE0
else .kuNn-$
break; zJ}abo6rVw
} mpk+]n@
} nTGf
catch(IOException e){e.printStackTrace ();} F?a 63,r
catch(Exception e){e.printStackTrace ();} "pK<d~Wu
0!%G#~th
%?+Lkj&
Utility.log(nFileLength); 0%&}wUjV
)XSHKPTQ1
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return nFileLength; yLCMu | +
} X0j>g^b8
Z~94<*LEp
fNx!'{o"
//保存下载信息（文件指针位置） ;?iu@h
private void write_nPos() @ls/3`E/5E
{ 1|G\&T
try{ nJv=kk1|o
output = new DataOutputStream(new FileOutputStream(tmpFile)); Y[PC<-fyf
output.writeInt(nStartPos.length); aLW3Ub{h
for(int i=0;i<nStartPos.length;i++) Sw>>]UjU
{ D[]0/+,
// output.writeLong(nPos); ipGxi[Vav
output.writeLong(fileSplitterFetch.nStartPos); 9wf"5c
output.writeLong(fileSplitterFetch.nEndPos); ZZHQ?p-
} Tzjv-9^V
output.close(); 0wTOdCvmb
} alzdYiGf
catch(IOException e){e.printStackTrace ();} tXrKC
catch(Exception e){e.printStackTrace ();} 58HAl_8W
} =IX-n$d`>
J{a9pr6
=c,7uB
//读取保存的下载信息（文件指针位置） JBc*m
private void read_nPos() *wJz0ex7R/
{ l-c:'n
try{ &D-z|ZjgHi
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #d[Nm+~ko
int nCount = input.readInt(); & uwOyb
nStartPos = new long[nCount]; VR"le&'z"
nEndPos = new long[nCount]; St!0MdCH
for(int i=0;i<nStartPos.length;i++) K@[Hej6d
{ #M!{D
nStartPos = input.readLong(); <{ v %2
nEndPos = input.readLong(); b[:m[^
} 7p!f+\kM
input.close(); ?771e:>S-
} b=sY%(2s
catch(IOException e){e.printStackTrace ();} }zkFl{/u
catch(Exception e){e.printStackTrace ();} `mD!z.`U
} jzpDKc%
J_yXL7d
`w4'DB-R)
private void processErrorCode(int nErrorCode) vA6onYjA
{ ()Wu_Q
System.err.println("Error Code : " + nErrorCode); jFKp~`/#
} (#85<|z
6)i>qz).
m-~3c]pA
//停止文件下载 LTA0WgzR)
public void siteStop() ,vMAX?c
{ gWjr|m<
bStop = true; wmR~e
for(int i=0;i<nStartPos.length;i++) ^@=4HtA
fileSplitterFetch.splitterStop(); Fo;J3<U)
yoe@]c=
=5^1Bl
} GJS(
} wXnVQ-6H
//负责部分文件的抓取 H*N{4zBB
**FileSplitterFetch.java iC!6g|]X
*/ Y%TY%"<
package NetFox; @aFk|.6
hD?6RVfG
sieC7raO
import java.io.*; E&t8nlTx
import java.net.*; Fx1FxwIJ
E^{!B]/oP
*+6iXMwe
public class FileSplitterFetch extends Thread { (5:pHX`P
f9y+-GhaD
pih 0ME}z
String sURL; //File URL r.Z g<T
long nStartPos; //File Snippet Start Position e9Gu`$K
long nEndPos; //File Snippet End Position ?+Vi !eS
int nThreadID; //Thread's ID H13\8Te{
boolean bDownOver = false; //Downing is over J2oh#TGp
boolean bStop = false; //Stop identical u+6D|
FileAccessI fileAccessI = null; //File Access interface T <k;^iqR
ld|GY>rH
6,~1^g*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 7l*vmF6Z
{ U6H3T0#
this.sURL = sURL; a\,V>}e
this.nStartPos = nStart; L"S2+F)n
this.nEndPos = nEnd; B2LXF3#/
nThreadID = id; y|0/;SjV
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p0CPeH
} a[rb-Z
o F_rC[
]b1>bv%
public void run() N|"kuRN#
{ +mR^I$9
while(nStartPos < nEndPos && !bStop) G*%U0OTi
{ H)&iFq
_):@C:6
;P8%yf
try{ `YZl2c<w*
URL url = new URL(sURL); tGXH)=K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O/(vimx.#F
httpConnection.setRequestProperty("User-Agent","NetFox"); c`S+>:
String sProperty = "bytes="+nStartPos+"-"; v,~fG>Y}
httpConnection.setRequestProperty("RANGE",sProperty); DMp@B]>
Utility.log(sProperty); 3'A0{(b
rp1+K4]P
>XiT[Ru
InputStream input = httpConnection.getInputStream(); 2w+4B4
//logResponseHead(httpConnection); {0/2Hw n
8gt*`]I
~5Mj:{B
byte[] b = new byte[1024]; N.nGez
int nRead; 'YbE%i}
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {+{p.
{ }F9#3W&`c
nStartPos += fileAccessI.write(b,0,nRead); Q9f5}
//if(nThreadID == 1) "8U=0a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); uz$p'Q
} ^k^?>h
EDnZ/)6Gg
fF#Fc&B
Utility.log("Thread " + nThreadID + " is over!"); ;GOu'34j
bDownOver = true; SGy2&{\Z
//nPos = fileAccessI.write (b,0,nRead); IBu\Sh-
} (LXYx<
catch(Exception e){e.printStackTrace ();} :Zob"*T
} 9Nv?j=*$
} =h ~n5wQG
v&]yzl
~>0H k}Hv
//打印回应的头信息 PVljb=8F
public void logResponseHead(HttpURLConnection con) 8)"lCIf
{ W|0))5a
for(int i=1;;i++) i!RYrae
{ GGhk`z
String header=con.getHeaderFieldKey(i); S^EAE]
if(header!=null) rb'mFqg*u
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eq&QWxiD*
Utility.log(header+" : "+con.getHeaderField(header)); &U}8@;
else W|n$H`;R
break; -rgdKA@)(
} yUxz,36wZ
} II~91IEk
R@_3?Z!W=
sD{Wc%5
public void splitterStop() kG}F/GN?
{ Ux=B*m1@{
bStop = true; 0mmHN`<
} k:@N6K/$P^
alNn(0MG
%Kp^wf#o9
} VUHf-bKl
E GZiWBr
7#9%,6Yi
/* EymSrZw
**FileAccess.java #O8=M(- V
*//文件访问(定位，写) [>3dhj[;
package NetFox; vW?/:
import java.io.*; Y}Y~?kE>M|
L?&&4%%
}ALli0n`V)
public class FileAccessI implements Serializable{ =iDd{$
Bx$?*y&f!v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UM]3MS:[
RandomAccessFile oSavedFile; m9&%A0
long nPos; ocUBSK|K)
ovXk~%_
q0vZR"y
public FileAccessI() throws IOException X*5N&AJ
{ Pv\8 \,B9
this("",0); \l 8_aj
} u3wd~.
Rxlv:
&2q<#b
public FileAccessI(String sName,long nPos) throws IOException +StsSZ
{ UK,sMKbl1
oSavedFile = new RandomAccessFile(sName,"rw"); l7@cov
this.nPos = nPos; &1`Y&x:p
oSavedFile.seek(nPos); H/;AlN|!
} <$25kb R5K
JV'aqnb.8\
j*4:4B%
public synchronized int write(byte[] b,int nStart,int nLen) G8/q&6f_
{ 3/]FT#l]i
int n = -1; CY[3%7fv
try{ DVKb`KJ"
oSavedFile.write(b,nStart,nLen); r=AA /n<
n = nLen; hk S:_e=
} UTN[!0[
catch(IOException e) .P?n<n#
{ g)|vS>^~
e.printStackTrace (); k"/Rjd(;
} 9e vQQN6D|
[fo#){3K
A^LS^!Jz
return n; 5IFzbL#q#f
} N`N?1!fM<}
Zkqq<
~ L>M-D4o
} h%4UeL &F
;#0$iE
Ze#DFe$
/* 7-}5 W
**SiteInfoBean.java e+4Eiv
*/ Z5)v
package NetFox; EYCZuJxv
9d(#/n
C+5X8
public class SiteInfoBean { Fr; 's(^
VEn3b
vX}w_Jj>
private String sSiteURL; //Site's URL <8Nr;96IA
private String sFilePath; //Saved File's Path 8pftc)k
private String sFileName; //Saved File's Name fk>{
private int nSplitter; //Count of Splited Downloading File ;c DMcKKIA
I|<]>D-8
&rPAW V'v
public SiteInfoBean() 6PS[OB{3
{//nSplitter的缺省值为5 SBDGms
//default value of nSplitter is 5 FH$q,BI!R
this("","","",5); _G'A]O/BZD
} x#zj0vI-8
A,=> |&*
1\Pjz Lj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u^CL }t*
{ - _6`0
sSiteURL= sURL; .9,x_\|G*
sFilePath = sPath; "bWx<
sFileName = sName; lQvgq
this.nSplitter = nSpiltter; J2! Q09 }5
iXL^[/}&?M
U?5lqq
} bX(/2_l
o76!7
kN8B,
public String getSSiteURL() ?TK`sGy
{ 5;^1Ab0
return sSiteURL; t,*1=S5
} )|k#cT{=M
UwF-*(#41
.QwB7+V4
public void setSSiteURL(String value) I.T?A9Z
{ %N`_g' r!
sSiteURL = value; 3/yt
} dC-~=}HR^
KRcB_(
sK&kp=zu
public String getSFilePath() @F$}/
{ {2D|,yH=
return sFilePath; X#ud5h
} v>Kh5H5e~
g;6/P2w
B, H9EX
public void setSFilePath(String value) D_~;!^
{ ]vn*eqd
sFilePath = value; SE6(3f$
} 1TR+p? "
|B*B>P#
BmccSC;o4
public String getSFileName() : xggo
{ ju"?b2f
return sFileName; <j,3Dn
} ^H1m8=
-o`K/f}d
QJrXn6`
public void setSFileName(String value) y"'p#j
{ KF1iYo>p
sFileName = value; % -AcA
} 1IS1P)4_0
?b{y#du2a
f5b|,JJ
public int getNSplitter() 3!fR'L/i
{ &0%Zb~ts
return nSplitter; dzAumWoh
} SG|AJ9
ge6S_"
=N{?ll6x7g
public void setNSplitter(int nCount) :l!sKT?:d!
{ l>pB\<LL
nSplitter = nCount; xRhGBb{@s
} RLF6Bc
} KB :JVK^<
HQ" trV
YlGUd~$`"+
/* YI"!&a'yj
**Utility.java X';qcn_^
*/ #0uu19+}
package NetFox; jQ%1lQ#R)
"5 ~{
sCzpNJ"8
public class Utility { A:GqR;;"x>
HJ]e%og
1Td`S1'#yg
public Utility() +ZW>JjP*
{ iQ8{N:58DN
Y$n+\K
r,0D I
} %aK[Yvo6
Xy 4k;+
//线程睡眠 )V[j~uOU)]
public static void sleep(int nSecond) p}1gac_c
{ DzE^FY
try{ /}>8|#U3y
Thread.sleep(nSecond); wzd(=*N
} 2)|=+DN;
catch(Exception e) GQY" +xa8]
{ YtSYe%
e.printStackTrace (); |gP)lR
} *P/A&"i[E
} o4EY2
S|k@D2k=
//日志 50-7L,
public static void log(String sMsg) ?&eS}skL
{ 0[%{YmI{W
System.err.println(sMsg); ||pOiR5
} W$SV+q(rT
OEjX(F3=
#@`c7SR
public static void log(int sMsg) wZ\93W-}
{ X;6;v]
System.err.println(sMsg); 1R~$m
} 6O6B8
} L%5y@b{AR
U!o
.u#Hg'oP
/* ; I-6H5
**TestMethod.java c|9g=DjK
*/ ?;`GCE
package NetFox; v@[3R7|4
\9V_[xD+
m]MR\E5]By
public class TestMethod { 5Wa)_@qI)`
XA;PWl5!
R--s u:
public TestMethod() '*rS,y
{ ///xx/weblogic60b2_win.exe 5~DKx7P!Z
try{ _$@fCo0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^K1mh9O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xPUukmG:B
SiteFileFetch fileFetch = new SiteFileFetch(bean); NJr)f
fileFetch.start(); zNKB'hsK
} H.{Fw j4
catch(Exception e){e.printStackTrace ();} T?!SEblP]
Wc+(xk
*#}=>, v
} iz/CC V L
gTTKjlI[
E8sM`2z5
public static void main(String[] args) Ar/P%$Zfq
{ pn(i18x
new TestMethod(); i7h^L)M
} M=;csazN
} p7`9 d1n
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