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)); m[rJFSpef
} -A~<IyPt
for(int i=0;i<nEndPos.length-1;i++) MsiSC
{ n%hnL$!z
nEndPos = nStartPos[i+1]; fz\Az-
} ?z.`rD$}(n
nEndPos[nEndPos.length-1] = nFileLength; q1j[eru
} "5FeP;
} ~M=`f{-$K
(nG
Si(?+bda0c
//启动子线程 ^|2qD: ;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; W*#/@/5
for(int i=0;i<nStartPos.length;i++) jLU)S)
{ xFh}%mwpt[
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >U].k8a)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), qxNV~aK
nStartPos,nEndPos,i); auU{Iy
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /fEXAk
fileSplitterFetch.start(); j(hC't-
} [VHt#JuN,
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GWsFW[T?~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `,z{70
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", mE1*F'0a
nEndPos = " + nFileLength); a'r\e2/e?H
// fileSplitterFetch[nPos.length-1].start(); 2TO1i0
Sr0mA M
Smo'&x
//等待子线程结束 tVwN92*J
//int count = 0; #';r 0?|
//是否结束while循环 Tbw8#[6AX
boolean breakWhile = false; 1{qg@xlj
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A}o1I1+
while(!bStop) H3b`)k sFr
{ "7d_$.Z
write_nPos(); K} @q+
Utility.sleep(500); {1mD(+pJ{
breakWhile = true; v2^CBKZ+
>{[J+f{~|
y[# U/2
for(int i=0;i<nStartPos.length;i++) Z~ (QV0}
{ j&r5oD;
if(!fileSplitterFetch.bDownOver) =6hf'lP
{ gvX7+F=}B
breakWhile = false; (uE_mEIsv
break; uQ}kq7gd
} 4_eq@'9-q
} DuaOi1Gw
if(breakWhile) )DW;Gc
break; .$rcTZ
_XN sDW4|
!q?}[E2
//count++; _[V 6s#Wk3
//if(count>4) zcc]5>
// siteStop(); [Fe5a
} U3>G9g>^B
>dO^pDSs
{chl+au*l
System.err.println("文件下载结束！"); g~]FI
} W/+0gh7`,(
catch(Exception e){e.printStackTrace ();} }5|uA/B
} q>?oV(sF
_nF_RpS
JL1Whf
//获得文件长度 M~v{\!S
public long getFileSize() d] {^
{ N6eY-`4y
int nFileLength = -1; 2gi`^%#k]
try{ FTn[$q
URL url = new URL(siteInfoBean.getSSiteURL()); 3Dy.mtP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5,A/6b
httpConnection.setRequestProperty("User-Agent","NetFox"); *l}q,9iQ-
cK""Xz&m
z`W$/tw"
int responseCode=httpConnection.getResponseCode(); ><Z2uJZ4x
if(responseCode>=400) 8AK#bna~-
{ gC?k6)p$N
processErrorCode(responseCode); @jfd.? RK!
return -2; //-2 represent access is error /Bc ;)~
} rd6?;K0
Ha<(~qf
)7f:hg
String sHeader; D`+'#%%x
8"? t6Z;5
7@:uVowQ
for(int i=1;;i++) +%0+
{ 8ARpjYZP
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q~`n%uYg\{
//Utility.log(in.readLine()); 9d v+u6)
sHeader=httpConnection.getHeaderFieldKey(i); "&An9H'
if(sHeader!=null) $WDa}~j~^
{ XWk^$"
if(sHeader.equals("Content-Length")) Xln'~5~)
{ o(}vR<tD\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TMbj]Mso
break; ) Limt<S
} yzYPT}t
} w%kxY5q
else `5 bHZ
break; >-Jutr<I"~
} ibh!8"[
} E[ ,Ur`>:
catch(IOException e){e.printStackTrace ();} \D0Pik@?
catch(Exception e){e.printStackTrace ();} S%'t )tt,
yB&s2J
|[0|j/V%O
Utility.log(nFileLength); 0nC%tCV'
R/iXO~/"J
SH"O<cDp
return nFileLength; jZ)1]Q2
} &uC7W.|
d+l@hgz~
]R(=)
//保存下载信息（文件指针位置） f"S^:F0
private void write_nPos() [H!V
{ ~R3@GaL1
try{ |#"<{RS+w
output = new DataOutputStream(new FileOutputStream(tmpFile)); Rb?6N
output.writeInt(nStartPos.length); 8^2Q ~{i
for(int i=0;i<nStartPos.length;i++) Xfe,ZC)
{ hH>t
// output.writeLong(nPos); =MA$xz3
output.writeLong(fileSplitterFetch.nStartPos); P@)zNik[
output.writeLong(fileSplitterFetch.nEndPos); lO[[iMHl<
} >%t"VpvR
output.close(); Y*0mC"n}
} ,_HVPE
catch(IOException e){e.printStackTrace ();} -B'<*Y
catch(Exception e){e.printStackTrace ();} M1^pf<!s
} A^xDAxk
+n7bbuxj(X
cZi/bIh
//读取保存的下载信息（文件指针位置） W2s6!_AN
private void read_nPos() Y'wQ(6ok
{ yi PMJ
try{ THC34u]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ;BsyN[bF
int nCount = input.readInt(); }Til $TT%H
nStartPos = new long[nCount]; x^&D8&4^
nEndPos = new long[nCount]; ry0P\wY}
for(int i=0;i<nStartPos.length;i++) !IF#L0z
{ pxjb^GZ0
nStartPos = input.readLong(); Bg{"{poy
nEndPos = input.readLong(); -Z9e}$q$,
} NvY%sx,
input.close(); (V5_q,2
} D}OvD |<-
catch(IOException e){e.printStackTrace ();} <7-3j{065
catch(Exception e){e.printStackTrace ();} 4vC { G.
} gy0l@ 5 N
[BWA$5D)Ny
=c:K(N qL
private void processErrorCode(int nErrorCode) 1$H*E~
{ Z$"E|nRN
System.err.println("Error Code : " + nErrorCode); 7Rwn{]r
} < j^8L^
J4EQhuQ
VG'M=O{)3
//停止文件下载 EVX*YGxx6
public void siteStop() jInI%
{ yz.a Z
bStop = true; 8R0Q-,'
for(int i=0;i<nStartPos.length;i++) ZjLuqo
fileSplitterFetch.splitterStop(); 0ZcvpR?G
8cI<~|4_
A%(t'z
} &?59{B.mD
} :(ni/,~Q
//负责部分文件的抓取 TL'^@Y7X5
**FileSplitterFetch.java g$+ $@~
*/ j6}/pe*;;T
package NetFox; O!xul$9
N;gI %6
}&!fT\4
import java.io.*; u)J&3Ah%
import java.net.*; GI']&{
v"-@'qN'
d|I?%LX0p
public class FileSplitterFetch extends Thread { kzozjh%`9h
"h58I)O
2Tt^^Lb
String sURL; //File URL 2z#gn9Wb
long nStartPos; //File Snippet Start Position I8M^]+c
long nEndPos; //File Snippet End Position 7 G37V"''
int nThreadID; //Thread's ID D[#6jJAb
boolean bDownOver = false; //Downing is over 4b5'nu
boolean bStop = false; //Stop identical JlaT -j
FileAccessI fileAccessI = null; //File Access interface H.-VfROi2
J7a_a>Y
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException oQ YmywY
{ `0)'&HbLY
this.sURL = sURL; |%\>+/j$
this.nStartPos = nStart; /fh[_!qN
this.nEndPos = nEnd; 'wA4}f
nThreadID = id; @ (4$<><
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5=@q!8a*
} K%i9S;~
:$qa
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public void run() A*b>@>2
{ T*pcS'?'
while(nStartPos < nEndPos && !bStop) N./l\NtZ
{ :^bjn3b
a]NH >d
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try{ dkUh[yo"H
URL url = new URL(sURL); 8>4@g!9E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \A#YL1hh
httpConnection.setRequestProperty("User-Agent","NetFox"); Ah#bj8}
String sProperty = "bytes="+nStartPos+"-"; #"&<^
httpConnection.setRequestProperty("RANGE",sProperty); 0[L)`7
Utility.log(sProperty); Wks?9)Is
^VL",Nt
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InputStream input = httpConnection.getInputStream(); 0Tp,b (;n
//logResponseHead(httpConnection); C]dK/~Z#r
>n(Ga9E
dAba'|Y
byte[] b = new byte[1024]; 1[4 2f#
int nRead; p#A{.6Pa:
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) OUM^u*
{ ^s.necg0
nStartPos += fileAccessI.write(b,0,nRead); vXI2u;=y
//if(nThreadID == 1) pXap<T
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YZ\a#s,0
} 4;;K1< 1
`514HgR
OK8|w]-A
Utility.log("Thread " + nThreadID + " is over!"); 2WF7^$^:
bDownOver = true; o W<Z8s;p
//nPos = fileAccessI.write (b,0,nRead); zqJ0pDS
} +5<]s+4T
catch(Exception e){e.printStackTrace ();} X<p'&
} xQKRUHDc
} -mfdngp3
JbR;E`8
XSBh+)0Ww
//打印回应的头信息 -h%!#g
public void logResponseHead(HttpURLConnection con) z\g6E/%%
{ 9fhgCu]$
for(int i=1;;i++) 8 o^ h\9I
{ Fi3k
String header=con.getHeaderFieldKey(i); P&kjtl68Y
if(header!=null) #t8{z~t3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); )}3!iDA
Utility.log(header+" : "+con.getHeaderField(header)); xPp\OuwK
else 0YsBAfRG
break; nm}wdel"
} VC T~"T2R
} n,l{1 q
(^lw<$N
j84g6;4Dv
public void splitterStop() ps@;Z?Q
{ 1&2X*$]y
bStop = true; ?7|6jTIs
} ]ucz8('
X}5}M+'~
xtq='s8e
} Ec4+wRWk85
P/?'ea
{3H)c^Q
/* rY:A LA
**FileAccess.java =G<i6%(^g
*//文件访问(定位，写) 7SVqfWp
package NetFox; K (!+l
import java.io.*; ?7k%4~H t
kD?lMA__
]>_Ie?L)<
public class FileAccessI implements Serializable{ v<u`wnt
S9VD/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 lO+6|oF0
RandomAccessFile oSavedFile; \2U FJ
long nPos; |A/)b78'u
>0c4C<_
:*<UCn""
public FileAccessI() throws IOException N*$L#L$*
{ .z6"(?~
this("",0); bsosva+
} .?^a|]
9]]isE8r
CtO;_;eD'
public FileAccessI(String sName,long nPos) throws IOException 0; PV gO;9
{ vCe]iB
oSavedFile = new RandomAccessFile(sName,"rw"); ^|kqy<<X
this.nPos = nPos; W? SFtz
oSavedFile.seek(nPos); uKF)'gj
} 1;FtQnvH
jMUN|(=Y
~u^MRe|`
public synchronized int write(byte[] b,int nStart,int nLen) Jv[c?6He
{ S#[w).7
int n = -1; ^6kE tTO*
try{ =F9!)r
oSavedFile.write(b,nStart,nLen); }:zTz%_K
n = nLen; a?K3/0G
} ZOIx+%/Vd#
catch(IOException e) O86[`,
{ E|~)"=
e.printStackTrace (); D.;iz>_}Y
} fC<pCdsg
x(r~<a[
PYhRP00}M
return n; 8G<{L0J%!
} e]Q bC"
kS)azV
edZhI
} eWw# T^
;GF+0~5>
o1^Rx5
/* $AyE6j_1gX
**SiteInfoBean.java 8H7=vk+
*/ %Ix
package NetFox; wUJ>?u9
T-)lnrs^
u,&[I^WK`C
public class SiteInfoBean { |J+oz7l?-
q7kE+z
24b?6^8~k
private String sSiteURL; //Site's URL U5!~@XjG>
private String sFilePath; //Saved File's Path tOT(!yz
private String sFileName; //Saved File's Name p?idl`?^3
private int nSplitter; //Count of Splited Downloading File ih\=mB
ra]lC7<H
L,7+26XV"B
public SiteInfoBean() `"RT(` m
{//nSplitter的缺省值为5 1/J3 9Y~+
//default value of nSplitter is 5 f:u3fL
this("","","",5); gF53[\w^v
} |g1~-
0E^6"nt7N
chs] ,7R
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QTLGM-Z
{ ww#]i&6
sSiteURL= sURL; viXt]0
sFilePath = sPath; @Lk!nP
sFileName = sName; SpJIEw
this.nSplitter = nSpiltter; hztxsvw
jn,_Ncd#
'5; /V
} U rL|r.
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AdGDs+at,
public String getSSiteURL() RIV + _}R
{ n5s2\(
return sSiteURL; 6*r#m%|
} |SSe n#PYp
!E.CpfaC
t;/s^-}
public void setSSiteURL(String value) b-Xc6f
{ J*nWCL
sSiteURL = value; /]>8V'e\
} }_|qDMk+
I;GbS`
pr.+r?la]
public String getSFilePath() 0hv}*NYd
{ 45aFH}w:
return sFilePath; ApSzkPv*
} 4qvE2W}&
ZgI?#e
efXiZ
public void setSFilePath(String value) #BhDC.CcW
{ p"tCMB
sFilePath = value; Wz&[cj
} Rn9e#_Az
H7?Sd(U
q<Z`<e
public String getSFileName() c5- 56Q
{ E E^lw61
return sFileName; DNu-Ce%
} HD!2|b~@
eo&^~OVT
q.s'z}
public void setSFileName(String value) L&LAh&%{2
{ 9YEE.=]T
sFileName = value; F9Co m}
} r$WBEt,B
cP2n,>:
Cc}3@Nf{/
public int getNSplitter() #w1E3ahaX
{ z{wZLqG
return nSplitter; E x)fXQ+
} WWgJ !Uz
%*a%F~Ss
mV++7DY
public void setNSplitter(int nCount) Lc! t
{ cTa$t :K@
nSplitter = nCount; 6R#.AD\
} b-?d(-
} ~jD~_JGp
GWW#\0*Bn
a%*W( 4=Y
/* vf0 fa46
**Utility.java (MzThGJK_
*/ .Ge`)_e
package NetFox; 5a%i%+;N
]QSQr*
k< $(
public class Utility { ~@d4p|K
g+%Pg@[
,Fzuo:{uy
public Utility() vn1*D-?
{ .kc{)d*0K
5b$QXO
z`:tl7
} (q}{;
,buo&DT{L
//线程睡眠 ]6;G#
public static void sleep(int nSecond) *3#RS
{ @d_9NOmNT
try{ ;MH_pE/m
Thread.sleep(nSecond); ZLlAK?N
} @pN6uDD}R
catch(Exception e) yW@YW_2;4
{ [Wn6d:
e.printStackTrace (); #3}!Q0
} yi:1cLq2
} 1k!$#1d<
=;{8)m
//日志 D!rD-e
public static void log(String sMsg) "Tnmn@
{ rYO~/N
System.err.println(sMsg); 'k9Qd:a}
} Z)!#+m83>-
%TYe]^/'y
1 EwCF
public static void log(int sMsg) jhB+ ]
{ |\T!,~
System.err.println(sMsg); S.|%dz
} }WnoI2
} chXTFLC~
UHS{X~CS e
p+}eP|N
/* d6ckvD[
**TestMethod.java iJb-F*_y
*/ >2ny/AK|
package NetFox; O2S{*D={
(".WJXB\
qdxDR 2]U
public class TestMethod { L8?;A9pc()
plgiQr #
7VW/v4n
public TestMethod() IPk"{T3
{ ///xx/weblogic60b2_win.exe C j:
try{ 'tY y_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4\y>pXML-U
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); DAQozhP8
SiteFileFetch fileFetch = new SiteFileFetch(bean); [E;~Y_l
fileFetch.start(); ;Swj`'7
} Voo_ ?
catch(Exception e){e.printStackTrace ();} N{?Qkkgx
,U=7#Cf!
VWW(=j
} O#`y;%
jBU!xCO
e_dsBmTh
public static void main(String[] args) Ns6CxE9
{ \9k{h08s
new TestMethod(); t'*2)U
} /_i]bM7W
} $!K,5^+
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