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)); Bqp&2zg)@
} w0X$rl1
for(int i=0;i<nEndPos.length-1;i++) >R#9\/s
{ d _uFY:
nEndPos = nStartPos[i+1]; g*28L[Q~
} w~n kNqm
nEndPos[nEndPos.length-1] = nFileLength; BPqwDjW
} m3B\)2B
} h)P]gT0f/
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@EYK(QS-
//启动子线程 (]}XLMi,|!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; $M-NR||k
for(int i=0;i<nStartPos.length;i++) QY@nE
{ j $KM9
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "s${!A)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), p#z;cjfSt
nStartPos,nEndPos,i); r.9 $y/5
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8>m1UONr
fileSplitterFetch.start(); ;}f6Y['z
} bYK]G+Ww
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hg{ &Y(J!U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M{G$Pk8[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jXtLo,km
nEndPos = " + nFileLength); o;%n,S8J|^
// fileSplitterFetch[nPos.length-1].start(); unpfA#&!"
YyG~#6aCh
~ J%m
//等待子线程结束 A=W5W5l(>
//int count = 0; \ x:_*`fU
//是否结束while循环 ~yd%~|
boolean breakWhile = false; XQ4dohGCP
c_t7RWV}
2=Jmi?k
while(!bStop) 7f[8ED[4
{ z(#=tC|
write_nPos(); aam1tm#Q
Utility.sleep(500); -}NAb^d
breakWhile = true; 8.PXTOhVL
Z5yt]-WN&
'H|;%J6d>
for(int i=0;i<nStartPos.length;i++) s!NisF
{ )\(lg*?:
if(!fileSplitterFetch.bDownOver) ~T;K-9R
{ X4XFu
breakWhile = false; e W9)@nVJ
break; 9DmSs=A
} t;oT {Hge
} G[vUOEU~O
if(breakWhile) a pKa4nI
break; g<0w/n!jmC
Ja^7$WY
J6= w:c
//count++; 1k*n1t):
//if(count>4) Hxj'38Y
// siteStop(); O\3r%=TF
} LRhP7D+A
R%qX_m\0
(R,NV3m?w
System.err.println("文件下载结束！"); \YjB+[.
} 3x,Aczb
catch(Exception e){e.printStackTrace ();} 4S^
} XryQ)x(
@"jmI&hYn
5?D1][
//获得文件长度 q#l.A?rK\
public long getFileSize() X S6]C{
{ f2BS[$oV4
int nFileLength = -1; 2Zv,K-G
try{ ;GiI'M
URL url = new URL(siteInfoBean.getSSiteURL()); nLzX Z6JlU
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V+P8P7y37B
httpConnection.setRequestProperty("User-Agent","NetFox"); /QV [N
'O!Z:-qE
n$nne6|O
int responseCode=httpConnection.getResponseCode(); TJeou#=/
if(responseCode>=400) H9.oVF^~
{ S(@*3]!q
processErrorCode(responseCode); _G_ &Me0
return -2; //-2 represent access is error kyp U&F
} fQ2!sV
GZxglU,3T
2nG{>,#C:O
String sHeader; Sn_z
i=,B88ko
~ra#UG\Y8
for(int i=1;;i++) 6RR4L^(m
{ e);bF>.~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1\M"`L/
//Utility.log(in.readLine()); ,Zf :R
sHeader=httpConnection.getHeaderFieldKey(i); Y*]l|)a6_]
if(sHeader!=null) =U)n`#6_j2
{ >u'/$k
if(sHeader.equals("Content-Length")) >#Grf)@"6
{ dqIZ#;:g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); D}=/w+
break; |JirBz
} j+z'
} AAeQ-nbP
else R^mu%dw)(%
break; p~v2XdR
} ,%"\\#3S
} 2@"0}po#
catch(IOException e){e.printStackTrace ();} ux"D ]P
catch(Exception e){e.printStackTrace ();} I,?Fqg'sq
9n06n$F
P wt ?9I
Utility.log(nFileLength); [)C)p*!Y)
c,b`N0dOKL
LAu+{'O\
return nFileLength; 0KWy?6 X
} 3n}sCEt=
WHhR)$zC
zLJ:U`uh\
//保存下载信息（文件指针位置） I@y2HxM
private void write_nPos() R#[QoyJ
{ ?15POY ?Z
try{ e/m'a|%:
output = new DataOutputStream(new FileOutputStream(tmpFile)); y<IZ|f
output.writeInt(nStartPos.length); tH<9
for(int i=0;i<nStartPos.length;i++) ovo?lE-a0
{ H4,.H,PZ
// output.writeLong(nPos); A?6{
output.writeLong(fileSplitterFetch.nStartPos); / h2*$
output.writeLong(fileSplitterFetch.nEndPos); 2@=cqD7x
} <;TP@-a
output.close(); ;XKo44%
} pqGf@24c<
catch(IOException e){e.printStackTrace ();} c_D,MW\IC
catch(Exception e){e.printStackTrace ();} )-TeDIfm
} 3cV+A]i
#XYLVee,
Jq$6$A,f
//读取保存的下载信息（文件指针位置） >8F{lbEe
private void read_nPos() E980yXJR
{ )Rm 'YmO
try{ :yFTaniJ'.
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eEg1-
int nCount = input.readInt(); \( Gf+
nStartPos = new long[nCount]; 7~%
nEndPos = new long[nCount]; Uy_}@50"l
for(int i=0;i<nStartPos.length;i++) LB64W ;#h
{ P?3YHa^up
nStartPos = input.readLong(); V5(tf'
nEndPos = input.readLong(); OyG_thX
} 7E\K!v_
input.close(); jl 30\M7
} {Vt^Xc
catch(IOException e){e.printStackTrace ();} >? A `C!i
catch(Exception e){e.printStackTrace ();} +QCU]Fozk
} =ihoVA:|
(c*7VO;
O>o}<t7
private void processErrorCode(int nErrorCode) k:+)$[t7
{ Xdp`Z'g
System.err.println("Error Code : " + nErrorCode); ]Gi+Z1q
} 2y .-4?e
hq&
j 44bF/
//停止文件下载 twJ|Jmd
public void siteStop() >X\s[d&(
{ [M8qU$&?]
bStop = true; xTksF?u)
for(int i=0;i<nStartPos.length;i++) t3yQ/
fileSplitterFetch.splitterStop(); %gne%9nn
E=tx.h4xG~
\3js}
} 4LKs'$:A=
} %RT6~0z
//负责部分文件的抓取 J!TK*\a2
**FileSplitterFetch.java `)( <g
*/ {TxVRpiP{Z
package NetFox; :vgh KI
JK'_P}[]I
HLyFyv\
import java.io.*; tr9_bl&z
import java.net.*; '@}?NV0
wYcz\uV
+y{93nl
public class FileSplitterFetch extends Thread { 3Av(|<cR
&:e}4/G
@y~BYiKs
String sURL; //File URL ]cGz~TN~
long nStartPos; //File Snippet Start Position j O5:{%
long nEndPos; //File Snippet End Position ym,Ot1
int nThreadID; //Thread's ID `Hp.%G(
boolean bDownOver = false; //Downing is over l)!woOt
boolean bStop = false; //Stop identical #&`WMLl+8
FileAccessI fileAccessI = null; //File Access interface &Ow?Hd0
,j(p}t
luxKgcU
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException +<9q]V
{ $=QGua V
this.sURL = sURL; lj SR?:\
this.nStartPos = nStart; KiRt'
this.nEndPos = nEnd; @)juP- o%
nThreadID = id; SUnmp
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r1az=$
} >.nt'BQ
"<n"A7e
/x8C70W^
public void run() *O}'2Ht6\
{ M]/wei"X
while(nStartPos < nEndPos && !bStop) .V)2Tz
{ ??e#E[bI
OTtanJ?
vdFQf ^l
try{ pil*/&pB
URL url = new URL(sURL); h C`p<jp/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); B| 0s4E
httpConnection.setRequestProperty("User-Agent","NetFox"); j C1^>D
String sProperty = "bytes="+nStartPos+"-"; jv#" vQ9A]
httpConnection.setRequestProperty("RANGE",sProperty); aXid;v,
Utility.log(sProperty); ht74h
d&R\7)0
rgvc5p
InputStream input = httpConnection.getInputStream(); t;f p<z7N.
//logResponseHead(httpConnection); ?[4khQt
s:Ql](/B#
r1[T:B'
byte[] b = new byte[1024]; n)?F 9Wap
int nRead; o? xR[N-J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) bHH}x"d[x
{ WZ V*J&
nStartPos += fileAccessI.write(b,0,nRead); {arjW3~M:
//if(nThreadID == 1) o-i.'L)X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %?G.lej,x
} K|J#/
@j8L{FGnN
&7kSLat+9{
Utility.log("Thread " + nThreadID + " is over!"); sbiDnRf
bDownOver = true; 3SB7)8Id1
//nPos = fileAccessI.write (b,0,nRead); /z-C :k\
} HE<%d
catch(Exception e){e.printStackTrace ();} r-"`Abev
} )Jjw}}$}Y
} (pxz#B4
&b]KMAo3
Z 7ZMu
//打印回应的头信息 :V1ZeNw
public void logResponseHead(HttpURLConnection con) l0bT_?LhK
{ ~)CU m[:oM
for(int i=1;;i++) Nn4Kt,KY
{ !I+u/f?TO7
String header=con.getHeaderFieldKey(i); 7a.#F]`
if(header!=null) 1Y0oo jD
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;8xn"G0}a
Utility.log(header+" : "+con.getHeaderField(header)); `DY4d$!4
else OZ]3OL,
break; F^v{Jqc
} eOmxA<h
} W)P_t"'@L
#7:9XID /
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public void splitterStop() ?lna8]t
{ e&7}N Za
bStop = true; v__Go kj-
} (C[S?@S
,&l*AB!
lVBy&f
} r ($t.iS
',ybHW%D%i
<6@NgSFz'
/* Oua/NF)
**FileAccess.java jM@I"JZb
*//文件访问(定位，写) 2"K~:Tm#w
package NetFox; !g:G{b
import java.io.*; O6 J<Lqgh
(c7{dYV
L ]'CA^N
public class FileAccessI implements Serializable{ 2%%U)|39mB
aRKG)0=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WC&Ltw8
RandomAccessFile oSavedFile; ,<WykeC
long nPos; lMf5F8
, &f20o
)8>f
public FileAccessI() throws IOException O g~"+IGp
{ {8Nd-WJ{
this("",0); lGgKzi9VD
} c{P`oB8
W n mRRq^
;rdLYmmx^
public FileAccessI(String sName,long nPos) throws IOException ]lG\t'R
{ &otgN<H9
oSavedFile = new RandomAccessFile(sName,"rw"); i58CA?
this.nPos = nPos; Yx/~8K_%M?
oSavedFile.seek(nPos); .`=PE&xq
} } R6h
j_<n~ri-
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public synchronized int write(byte[] b,int nStart,int nLen) 3&2q\]Y,
{ P@?'@.e
int n = -1; } dlNMW
try{ ?uBC{KQ}Y
oSavedFile.write(b,nStart,nLen); /Bu5kBC
n = nLen; };sm8P{M
} ~"B[6^sW
catch(IOException e) s*WfRY*=V
{ /T(~T
e.printStackTrace (); k&;L(D
} 6>A8#VT
} ~bOP^'
ar}759
return n; -"L6^IH7
} >k-poBw
:Djp\ e6!
SSC!BcC1
} MUl+Oy>
b=l}|)a
]TOY_K8"z#
/* VX%\_@
**SiteInfoBean.java /L Tyiiz6
*/ 6K0*?j{;"
package NetFox; nClU5
&|;!St]!M
xKux5u_
public class SiteInfoBean { ".Ug A\0
wQ.zj`?$(
Zt=X %M|aw
private String sSiteURL; //Site's URL 9q{dRS[A
private String sFilePath; //Saved File's Path |7fBiVo
private String sFileName; //Saved File's Name XITQB|C??$
private int nSplitter; //Count of Splited Downloading File u'>CU
1 j8,Zrg1
,:,|A/U
public SiteInfoBean() 9]\vw
{//nSplitter的缺省值为5 5+Ut]AL5
//default value of nSplitter is 5 n|6yz[N
this("","","",5); K.7gd1I
} `9gx-')]\
jm"xf7
_v,n~a}&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g5[3[Z(.
{ vt,X:3
sSiteURL= sURL; Kwnu|8
sFilePath = sPath; ~3 (>_r
sFileName = sName; ^"-2fJ
this.nSplitter = nSpiltter; ma~`&\xE
"$Q Gifb
^Pwq`GA
} VGIc|Q=F
>MH@FnUL
"{lnSLk
public String getSSiteURL() jL$X3QS:
{ *PPFk.#x
return sSiteURL; 1[ Pbsb
} Q1yTDJ(2
C5z4%,`f
i/Z5/(zF
public void setSSiteURL(String value) *UC^&5:
{ na)_8r~
sSiteURL = value; <^paRKEa+#
} {HeMdGn9
kOO2 ?L|Z
cs)hq4-L`
public String getSFilePath() 2]wh1)
{ ]&>)=b!,
return sFilePath; #96a7K
} Y*f<\z(4
LTHS&3%2
S;~_9i]upe
public void setSFilePath(String value) F(r&:3!97
{ V96BtVsB
sFilePath = value; S"l&=J2dc
} teb(\% ,
VM`."un]
f63q
public String getSFileName() KtE`L4tW6
{ /~:ztv\$M"
return sFileName; 78wcMQNX9
} Kt(p|
q$P"o].EK
_U %B1s3y
public void setSFileName(String value) @z.!Dby
{ t{9Ph]e
sFileName = value; r%4:,{HF
} "P~>AXcq
CAO$Zt
M=%p$\x
public int getNSplitter() 6._):[_2
{ .jU9{;[
return nSplitter; H b.oKo$T
} bmLNR
A|^?.uIM
u CXd% CzE
public void setNSplitter(int nCount) :>=,sLfJ
{ NNX/2
nSplitter = nCount; _>.%X45xi
} (,>`\\
} bc-"If Z&
_"n4SXhq
|Cm}%sgR\0
/* 4p]Y`];U
**Utility.java %{Gqhb=u\
*/ 5"+* c@L
package NetFox; i~4Kek6,I
S1."2AxO
s*;~CH-[
public class Utility { UOyP6ej
HhO$`YZ%>
8wOr`ho B
public Utility() ]?2AFkF
{ XB?!V|bno
I`|>'$E[r
4dO>L"
} u4Sa4o
v'uQ'CiH
//线程睡眠 IKt9=Tx
public static void sleep(int nSecond) D~<GVp5T
{ fN9hBC@
try{ 2-]m#}zbP
Thread.sleep(nSecond); {)+/w"^.
} >z2{D7
catch(Exception e) -v:Y\=[\
{ ${?Px c{-
e.printStackTrace (); ZISR]xay
} ;-3M
} W$y?~2
"H({kmR
//日志 x-"7{@lz
public static void log(String sMsg) N4Ym[l
{ eWFlJ;=
System.err.println(sMsg); z}5XLa^
} \%K6T)9
9X-DR
=LC5o2bLy
public static void log(int sMsg) = #`FXO1C
{ Q{%ow:;s*
System.err.println(sMsg); lm+wjhkN
} `bi5#xR
} GRNH!:e
yfU1;MI
|1neCP@ng
/* E^rN)
**TestMethod.java rkD(KG9E
*/ %Z.!Bm:
package NetFox; EV}%D9:
Xd4~N:
D=8=wT2<
public class TestMethod { f~53:;L/
bY`k`3v
E yNCky
public TestMethod() /<n_X:[)
{ ///xx/weblogic60b2_win.exe Fax73vl|^a
try{ u`ZnxD>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); =Vi+wH{xM
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); , vR4x:W
SiteFileFetch fileFetch = new SiteFileFetch(bean); }\9qN!ol
fileFetch.start(); Q5Wb)
} ]UNmhF!W>u
catch(Exception e){e.printStackTrace ();} 5EU3BVu&u
B%,0zb+-L
AojX)_"z
} 4|~o<t8
(|WqOwmoUt
8.vD]hO
public static void main(String[] args) ^*ZO@GNL
{ 0_ ;-QAd
new TestMethod(); |{$Vk%cUE
} H.YntFtD'
} #e=[W))
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