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)); t}eyfflZ
} %]Z4b;W[Y
for(int i=0;i<nEndPos.length-1;i++) K ~mUO
{ aG]>{(~cL
nEndPos = nStartPos[i+1]; pA*C|g
} w*6b%h%ww
nEndPos[nEndPos.length-1] = nFileLength; -g~+9/;n
} .f_ A%
} \<pr28
y;ElSt;S
:C>7HEh-2_
//启动子线程 'O(=Pz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Gt.'_hf Js
for(int i=0;i<nStartPos.length;i++) wNHn.
{ sm-[=d%@L
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 83c2y;|8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QP%_2m>yhl
nStartPos,nEndPos,i); o=YOn&@%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); M?lh1Yu"
fileSplitterFetch.start(); }R}+8
} #Kb /tOp1
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >SI'Q7k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M,fL(b;2
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", n.+'9Fj
nEndPos = " + nFileLength); wS}c\!@<,
// fileSplitterFetch[nPos.length-1].start(); o^/ #i`)
|@AXW
Y_CVDKdcY
//等待子线程结束 V^,gpTyv*
//int count = 0; nW)+-Wxq
//是否结束while循环 /i"hViCrlG
boolean breakWhile = false; &q>8D'
6=;:[
$/M-@3wro
while(!bStop) Z i6s0Uck
{ hty'L61\z
write_nPos(); fLe~X!#HF
Utility.sleep(500); ZoXz@/T
breakWhile = true; z&gmaYwq
(S!UnBb&
`2 <:$]
for(int i=0;i<nStartPos.length;i++) itzUq,T
{ B2[f1IMI
if(!fileSplitterFetch.bDownOver) }i!+d,|f
{ .rK0C)
breakWhile = false; geR :FO;\
break; yq-~5ui
} Q|)>9m!tt
} %NQ%6B
if(breakWhile) ,LA'^I?
break; R0=f`;
`a&L
<2)AbI+3
//count++; .~o{i_JH
//if(count>4) eaFkDl
// siteStop(); hTDGgSG^
} *5PQ>d G
naaKAZ!S
|<c9ZS+
System.err.println("文件下载结束！"); ,7s>#b'
} b23A&1X
catch(Exception e){e.printStackTrace ();} n0=]C%wr
} &|XgWZS5
yF)J7a:U
zjUQ]
//获得文件长度 Gt&yz"?D
public long getFileSize() >.qFhO\1so
{ iLnW5yy
int nFileLength = -1; 4<($ZN8
try{ +S{m!j%B
URL url = new URL(siteInfoBean.getSSiteURL()); zls^JTE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); zdwQpB,+^
httpConnection.setRequestProperty("User-Agent","NetFox"); @m5J%8>k
:=hL}(~]
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int responseCode=httpConnection.getResponseCode(); "zq'nV=
if(responseCode>=400) )3CM9P'0
{ b;VIR,2
processErrorCode(responseCode); ''9]`B,:a0
return -2; //-2 represent access is error G%sO{k7
} 6vK`J"d{~D
GUu8 N
R%3yxnM*
String sHeader; Z@euO~e~
fZ-"._9UyH
%$ya>0?mq
for(int i=1;;i++) b*Qd9
{ IIAp-Y~B
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W_wC"?A%
//Utility.log(in.readLine()); \NNA"
sHeader=httpConnection.getHeaderFieldKey(i); C)U4Fr ?E:
if(sHeader!=null) M1eh4IVE?
{ sR/Yv
if(sHeader.equals("Content-Length")) -Hm"Dx
{ .8QhJHwd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ug]2wftlQ
break; fR[8O\U~
} ;:=j{,&dl[
} _AF$E"f@
else FC+-|1?C
break; Ou1kSG|kM
} $?F_Qsy{d
} d9JAt-6z2
catch(IOException e){e.printStackTrace ();} RP2$(%
catch(Exception e){e.printStackTrace ();} O.FTToh<
gba1R
rCa]T@=
Utility.log(nFileLength); 3YLK?X8
P1OYS\
drAJ-ii
return nFileLength; :WWHEZK
} h.?<(I
ky|kg@n{
B-LV/WJ_
//保存下载信息（文件指针位置） UhJS=YvT
private void write_nPos() lai@,_<GV
{ eM!Oc$C8[
try{ Ly(iq
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0dwD ?GG2
output.writeInt(nStartPos.length); ^JxVs 7
for(int i=0;i<nStartPos.length;i++) 6/cm TT$i
{ ED8{
// output.writeLong(nPos); %S^ke`MhF
output.writeLong(fileSplitterFetch.nStartPos); 5:38}p9`
output.writeLong(fileSplitterFetch.nEndPos); 7d.H8C2
} U`) ";WN
output.close(); s>L-0vG
} d1#lC*.Sg
catch(IOException e){e.printStackTrace ();} cWnEp';.
catch(Exception e){e.printStackTrace ();} ;L:UYhDbUx
} oTvg%bX
z@UH[>^gj
1;m?:|6K{
//读取保存的下载信息（文件指针位置） AM?ZhM
private void read_nPos() \GHj_r
{ gIweL{Pc
try{ )r"R
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Z<|x6%
int nCount = input.readInt(); B[mZQ&Gz`a
nStartPos = new long[nCount]; vV"YgN:
nEndPos = new long[nCount]; v3[ZPc;;
for(int i=0;i<nStartPos.length;i++) Ew]&~:$Ki
{ LntRLB'
nStartPos = input.readLong(); +mG"m hF
nEndPos = input.readLong(); T=w0T-[f
} j7);N
input.close(); [|$C2Dhw=
} GF@`~im
catch(IOException e){e.printStackTrace ();} ug}u>vQ>
catch(Exception e){e.printStackTrace ();} :{eYm|2-
} sz%]rN6$
4NRj>y
D+AkV|
private void processErrorCode(int nErrorCode) !|9@f$Jv
{ 0xi2VN"X
System.err.println("Error Code : " + nErrorCode); `!X8Cn
} IRLAsb3
"$5cKbJ
QX?moW6UW
//停止文件下载 yz3=#
public void siteStop() ^VzhjKSu
{ 7lYf+&JZ
bStop = true; fvta<
for(int i=0;i<nStartPos.length;i++) }x6)}sz7
fileSplitterFetch.splitterStop(); "w 4^i!\
43=)akJi
YpZuAJm<2_
} ~2[kCuu
} T g(\7Kq
//负责部分文件的抓取 L5:1dF
**FileSplitterFetch.java nCV7(ldmH
*/ B{`K?e0
package NetFox; +bso4 }rS
q+qF;7dN@
) F -8
import java.io.*; wtL=^
import java.net.*; uCt?(E>
&n?RKcH}d
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public class FileSplitterFetch extends Thread { "KCG']DF
J10/pS
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String sURL; //File URL kg(}%Ih
long nStartPos; //File Snippet Start Position asQ^33g z
long nEndPos; //File Snippet End Position SPe%9J+
int nThreadID; //Thread's ID cAx$W6S
boolean bDownOver = false; //Downing is over ,ZYPffu<*
boolean bStop = false; //Stop identical _^?_Vb
FileAccessI fileAccessI = null; //File Access interface nql{k/6
3 %BI+1&T_
F1}d@^K 7d
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 6%9 kc+ 9
{ Rc93Fb-Zp
this.sURL = sURL; u>] )q7s
this.nStartPos = nStart; a$iDn_{
this.nEndPos = nEnd; D0_CDdW%7
nThreadID = id; =^zGn+@z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Fv(FRZ)
} N3Q .4? z9
Z>/ *q2
W3('1
public void run() ]T40VGJ:h
{ o*~=NoR
while(nStartPos < nEndPos && !bStop) O<AGAD
{ <v\$r2C*
wqjR-$c
r~|7paX!
try{ ^\S~rW.3_
URL url = new URL(sURL); x'G_z_<V
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q`O~f<a
httpConnection.setRequestProperty("User-Agent","NetFox"); bO('y@)X
String sProperty = "bytes="+nStartPos+"-"; );S8`V
httpConnection.setRequestProperty("RANGE",sProperty); ^IvQdVB
Utility.log(sProperty); E&"V~
00>knCe6
aU.!+e%_
InputStream input = httpConnection.getInputStream(); EpT^r8I
//logResponseHead(httpConnection); 8B "^}y\0
&\ad.O/Q
U.Z5;E0:
byte[] b = new byte[1024]; 0Bkc93
int nRead; 5)rN#_BKj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) :Ez*<;pF'
{ }0/l48G
nStartPos += fileAccessI.write(b,0,nRead); WS@"8+re;
//if(nThreadID == 1) osO\ib_%
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B<.ZW}#v
} EZp >Cf7
]W`M <hEI
8F$]@0v`%
Utility.log("Thread " + nThreadID + " is over!"); BEAY}P(y3
bDownOver = true; dtG>iJ
//nPos = fileAccessI.write (b,0,nRead); gL@]p
} O"X7 DgbC
catch(Exception e){e.printStackTrace ();} [1Qg *
} +'w6=qI
} d&ff1(j(
[_KOU2
DHvZ:)aT}
//打印回应的头信息 A&jR-%JG
public void logResponseHead(HttpURLConnection con) e?o/H
{ p&2d&;Qo0
for(int i=1;;i++) (_N(K`4#W
{ U9\w)D|+eE
String header=con.getHeaderFieldKey(i); DdeKZ)8
if(header!=null) ]Ee$ulJ02
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eT2Tg5Etc
Utility.log(header+" : "+con.getHeaderField(header)); s I0:<6W
else `4Fw,:+e
break; m,5?|J=
} lG[j,MDs
} qJ~fEX
Da)_OJYE
puh-\Q/P
public void splitterStop() !@arPN$
{ tu;Pm4q7
bStop = true; <a+@4d;
} B<G,{k
w)R5@ @C*
Zx: h)I
} j(>xP*il
ZP0D)@8
+KTHZpp!c2
/* .jbxA2
**FileAccess.java CFoR!r:X
*//文件访问(定位，写) r&F 6ZCw
package NetFox; 4`o<e)c3
import java.io.*; \0e`sOS`L
Vkf{dHjW
\zDs3Hp
public class FileAccessI implements Serializable{ 5Z:qU{[
7^d7:1M
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \W\*'C8q\
RandomAccessFile oSavedFile; 9pWSvalw9
long nPos; *dC&*6Rx
6y^GMlsI
{lppv(U
public FileAccessI() throws IOException Bob-qCBV
{ >4+KEK
this("",0); h$6~3^g:P
} 0x^lHBYc
5x,/p
hL}ZPHA
public FileAccessI(String sName,long nPos) throws IOException cT;Zz5
{ t4hc X[
oSavedFile = new RandomAccessFile(sName,"rw"); &Du S*
this.nPos = nPos; T_9o0Qk
oSavedFile.seek(nPos); mGJRCK_
} "];@N!dA
z'"Y+EWN
1FT3d
public synchronized int write(byte[] b,int nStart,int nLen) Pl2eDv-y
{ bg)}-]u]
int n = -1; g^\!> i
try{ h7o.RRhK
oSavedFile.write(b,nStart,nLen); $Fy>N>,E(
n = nLen; eYu0")
} :s-9@Yl|
catch(IOException e) 9E[==2TO
{ Ua=r24fy
e.printStackTrace (); mwI7[I2q
} $>+g)
>Ml5QO$*.q
*{\))Zmhd
return n; (<e<Q~(
} #nAq~@X
jCIY(/
[r'A8!/|[
} ki1j~q
&H+n0v
' d?6 L
/* 7lKatk+7K
**SiteInfoBean.java "I9r>=
*/ ~mMTfC~9
package NetFox; >6)|>#Wi
lJT"aXt'M
7;&,LH
public class SiteInfoBean { Sn' +~6i
L1y71+iqU
Vobq|Rd/%
private String sSiteURL; //Site's URL lWT`y
private String sFilePath; //Saved File's Path <vD(,||
private String sFileName; //Saved File's Name n.C5w8f
private int nSplitter; //Count of Splited Downloading File H/={RuU
sNP ;
( 5uSqw&U
public SiteInfoBean() (Fq:G) $
{//nSplitter的缺省值为5 9b@yDq3hQ
//default value of nSplitter is 5 tE-g]y3
this("","","",5); 1xh7KBr,
} Z/|=@gpw
:3b02}b7
Q(e
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 8.+ yZTg
{ :fq4oHA#
sSiteURL= sURL; Ps[#z@5{x
sFilePath = sPath; %&q}5Y4!
sFileName = sName; -~X[j2
this.nSplitter = nSpiltter; 6E9/z
aUA)p}/:
tCar:p4$
} #3'M>SaoH
kQQDaZ8
*v?kp>O
public String getSSiteURL() 0'YJczDq:7
{ 5}Xi`'g,
return sSiteURL; NSH4 @x
} ~-B+7
1MT,A_L
f*9O39&|
public void setSSiteURL(String value) 7q5*grm
{ Z&P\}mm
sSiteURL = value; mVh;=>8K
} BBv+*jj
"^a"`?J
)S/=5Uc
public String getSFilePath() V w58w`e
{ 8F@Sy,D
return sFilePath; m7u`r(&
} 0z4M/WrNt
ItZYOt|Hn
ju.pQ=PSX
public void setSFilePath(String value) rPqM&&+
{ a(D=ZKbVU
sFilePath = value; 9 %i\)
} ~131|e`C
p8?v o?^
>}W[>WReI
public String getSFileName() HXztEEK6
{ bS954d/
return sFileName; %\n|2*r
} ffBd
a7453s
`(=Kp=b
public void setSFileName(String value) 7mMMVz2
{ cO5zg<wF
sFileName = value; +mzLOJed
} $bFK2yx?=
zNdkwj p+
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public int getNSplitter() kfT*G +l]
{ s(J>yd=
return nSplitter; FF!PmfF'
} ela^L_NhF
mtn^+*
U V*Ruy-
public void setNSplitter(int nCount) J%M [8
{ 6)P.wW
nSplitter = nCount; CH 29kQ
} NY.* S6
} ~(kqq#=s
Ke?,AWfG
KAI2[ gs
/* 79exZ7|
**Utility.java hpPacN
*/ 8T6NG!/
package NetFox; hh&$xlO)(v
o ]z#~^w
}u=Oi@~
public class Utility { ^2+Vt=*
D&D6!jz
) ba~7A
public Utility() lv'WRS'}
{ '?L^Fa_H
kLZVTVSJt
]+W){W=ai
} O=(F46 M
EwA*
//线程睡眠 4gsQ:3
public static void sleep(int nSecond) 7bihP@I!
{ ZDgT"53
try{ ,m5i(WL
Thread.sleep(nSecond); p\lR1
} UU MB"3e
catch(Exception e) 6[c|14l
{ !$oa6*<1
e.printStackTrace (); %xOxMK@
} |%v:>XEO
} G2)F<Y
}X^MB
//日志 ,aC}0t
public static void log(String sMsg) :TG;W,`.V
{ c {%mi
System.err.println(sMsg); -OlrA{=c_
} 10*Tk 8
XGH:'^o_
AJxN9[Z!N
public static void log(int sMsg) }9fch9>Zr
{ jYRSV7d
System.err.println(sMsg); nW7: ]
} bS r"k
} j9hfW'
=2Yt[8';
YZ4`b-
/* KGg S"d
**TestMethod.java "g&f:[a/
*/ H~:oW~Ah
package NetFox; -ZZJk-::
?{J1Uw<
3zD#V3=
public class TestMethod { GyN|beou
c]aU}[s1
t~/:St
public TestMethod() 9$;5J
{ ///xx/weblogic60b2_win.exe -oyA5Yx0
try{ rSJ!vQo Cb
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ]B=*p0~j^n
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); T:X*
SiteFileFetch fileFetch = new SiteFileFetch(bean); O& Sk}^
fileFetch.start(); $jE<n/8
} EOXkMr
catch(Exception e){e.printStackTrace ();} <KU0K
hQm=9gS
0't)-Pj+,
} =CK%Zo
Jcze.t
M?"4{
public static void main(String[] args) f/UU{vX(
{ O0L]xr
new TestMethod(); s)r!3HS
} "I/05k K
} K {v^Y,B
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