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[T!AO-S$
} p:U{3uN 62
for(int i=0;i<nEndPos.length-1;i++) 3^&pb
{ ]@1ncn7N
nEndPos = nStartPos[i+1]; RzSN,bLR
} p7O4CP>9[
nEndPos[nEndPos.length-1] = nFileLength; p/s5[>N
} CV7.hF<
} z!j`Qoh?V9
WHF:>0B
XlNB9\"5
//启动子线程 s*}d`"YvH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0$49X
for(int i=0;i<nStartPos.length;i++) 2I39fZa
{ Un[#zh<4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &jPsdv h
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gzdgnF2
nStartPos,nEndPos,i); 8|Y^z_C
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~yf5$~Z
fileSplitterFetch.start(); MN)<Tr2f
} mKq9mA"(E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `Op ";E88
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %s)E}cGH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~GY;{
nEndPos = " + nFileLength); IWpUbD|kC
// fileSplitterFetch[nPos.length-1].start(); Q{Bj(f
7y`~T+
2W~2Hk=0+%
//等待子线程结束 TT&!WbA-Hk
//int count = 0; o_$r*Z|HG
//是否结束while循环 RMrt4:-DI
boolean breakWhile = false; gA) F
uTJ?@^nq
\S2'3SDd/
while(!bStop) Wj*6}N/
{ wy&*6>.
write_nPos(); O "h+i>|l
Utility.sleep(500); #QDV_ziE5
breakWhile = true; XJ NKM~
,wEM
{k]VT4/
for(int i=0;i<nStartPos.length;i++) `RzM)ILl
{ \1B*iW
if(!fileSplitterFetch.bDownOver) SoY&R=
{ Ia"bP` L
breakWhile = false; :3Jh f$
break; I5"=b}V5
} u})JQ<|
} \)"qN^we
if(breakWhile) NAocmbfNz
break; -jw=Iyv
"7 4L
]V]o%onW
//count++; XF$C)id2p
//if(count>4) nW%c95E
// siteStop(); BPOWo8TqD^
} &]c9}Ic
dCyQCA[
*:_hOOT+[
System.err.println("文件下载结束！"); f3h9CV
} Y\x Xo?
catch(Exception e){e.printStackTrace ();} Qqaf\$X
} QtzHr
bcE DjLXq
~5#7i_%@E}
//获得文件长度 wLbnsqa
public long getFileSize() Y{'G2)e
{ Stw6%T-
int nFileLength = -1; y|mR'{$I
try{ gy[uqm_ T
URL url = new URL(siteInfoBean.getSSiteURL()); \ a<Ye T
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1wM p3
httpConnection.setRequestProperty("User-Agent","NetFox"); 1|89-Ii]
5~? J
abv]
int responseCode=httpConnection.getResponseCode(); TP^0`L
if(responseCode>=400) 0nuFWV
{ A,/S/_Q=
processErrorCode(responseCode); P$QfcJq&c*
return -2; //-2 represent access is error 3WVHI$A9
} $_UF9l0
&pAT
pQhv3F
String sHeader; GgYomR:
Vqr&)i"b$
eyWwE%
for(int i=1;;i++) DQ}]'*@?
{ iB`m!g6$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -|kDa1knA
//Utility.log(in.readLine()); YD%Kd&es
sHeader=httpConnection.getHeaderFieldKey(i); +Lr0i_al
if(sHeader!=null) N!3f1d7RQ
{ ;vx9xs?6
if(sHeader.equals("Content-Length")) HTG;'$H^
{ /P%:u0fX,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >JMKEHl.q
break; S'e2~-p0F
} I|:j~EY
} aU!UY(
else @mazwr{B
break; re*/JkDq3K
} V]2z5u_q
} kShniN
catch(IOException e){e.printStackTrace ();} ublY!Af
catch(Exception e){e.printStackTrace ();} YGO@X(ej,
$} Myj'`r
|+bG~~~%j
Utility.log(nFileLength); .,,73"
.wSAysiQ|P
v>5F[0gE
return nFileLength; B+LNDnjO]
} V_kE"W)
sFTIRVXN,
jj2UUQ|
//保存下载信息（文件指针位置） 4Ojw&ys@V
private void write_nPos() U{Z>y?V/
{ ^J_hkw~gO
try{ ,d+mT^jN
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2vC=.1k
output.writeInt(nStartPos.length); 2 *$n?
for(int i=0;i<nStartPos.length;i++) K&h6#[^\d
{ DPOPRi~
// output.writeLong(nPos); Ah`dt8t
output.writeLong(fileSplitterFetch.nStartPos); 4@I]PG
output.writeLong(fileSplitterFetch.nEndPos); EUkNh>U?
} =)8Ct
output.close(); 68*{Lo?U
} _;{-w%Vf
catch(IOException e){e.printStackTrace ();} qg/5m;U
catch(Exception e){e.printStackTrace ();} gib]#n1!p
} z"#.o^5
!)=o,sVA
CmOb+:4@K
//读取保存的下载信息（文件指针位置） Ul Iw&U
private void read_nPos() EoeEg,'~F
{ EiUV?Gvz
try{ P$Q&xN<#)
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~aG-^BAS
int nCount = input.readInt(); (Nahtx!/9
nStartPos = new long[nCount]; %"zJsYQ!
nEndPos = new long[nCount]; Biwdb
for(int i=0;i<nStartPos.length;i++) $5r,Q{;$
{ O@rb4(
nStartPos = input.readLong(); }TW=eu~
nEndPos = input.readLong(); !*gAGt_
} >``GDjcJ
input.close(); ,GIqRT4K
} |Y11sDa9h
catch(IOException e){e.printStackTrace ();} ]r6bJ2
catch(Exception e){e.printStackTrace ();} Bl];^W^P
} 6pR#z@,
aw1J#5j`n
HV.7IyBA^
private void processErrorCode(int nErrorCode) X;:xGZ-oY
{ f,>i%.
System.err.println("Error Code : " + nErrorCode); ex458^N_
} ]o$/xP
rUjr'O0
G65N:
//停止文件下载 D$E9%'ir
public void siteStop() `t&;Yk]-L
{ C5UDez
bStop = true; S+Yg!RrNqj
for(int i=0;i<nStartPos.length;i++) ;g jp&g9Q
fileSplitterFetch.splitterStop(); 6,1|y%(f
5QJL0fc
h$\hPLx
} us%RQ8=k
} zQ}N mlk
//负责部分文件的抓取 CaBS0' n
**FileSplitterFetch.java %LHV0u
*/ [Gy'0P(EQ
package NetFox; V?BVk8D};
Pltju4.:C
K3DJ"NJ<Ji
import java.io.*; -d'|X`^nE
import java.net.*; GNc|)$
,0]28D
nn4Sy,cz
public class FileSplitterFetch extends Thread { FaE orQ
g"S+V#R
d A{Jk
String sURL; //File URL T(^8ki
long nStartPos; //File Snippet Start Position gq3OCA!cX
long nEndPos; //File Snippet End Position GuvF
int nThreadID; //Thread's ID |LE++t*X~
boolean bDownOver = false; //Downing is over mtddLd,
boolean bStop = false; //Stop identical e622{dfVS
FileAccessI fileAccessI = null; //File Access interface v^fOT5\
lG>e6[Wc
^\jX5)2{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W%K8HAP"
{ 4CT9-2UC
this.sURL = sURL; z,YUguc|
this.nStartPos = nStart; S=SncMO nE
this.nEndPos = nEnd; Cpv%s 1M
nThreadID = id; $4JX#lkt
fileAccessI = new FileAccessI(sName,nStartPos);//定位 $#3<rcOq
} "IJMvTmj
[Od9,XBa
.fY<"2g
public void run() l>Ja[`X@
{ y4rJ-
while(nStartPos < nEndPos && !bStop) Z3>3&|&
{ _)2TLA n3
>Eg.c
+N:6wZ7<f
try{ xGv,%'u\
URL url = new URL(sURL); G;c0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6RQCKN)
httpConnection.setRequestProperty("User-Agent","NetFox"); k+GnF00N^8
String sProperty = "bytes="+nStartPos+"-"; bI6wE'h
httpConnection.setRequestProperty("RANGE",sProperty); <SdJM1%Qo
Utility.log(sProperty); .eB"la|d
{eN{Zh5"
FKnQwX.0
InputStream input = httpConnection.getInputStream(); VQjFEJ
//logResponseHead(httpConnection); 1";e'?^x
SliQwm5
-G#@BtB2+
byte[] b = new byte[1024]; EiP&Y,vT
int nRead; (A fbS=[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) '4lT*KN7\
{ wf<`J/7u
nStartPos += fileAccessI.write(b,0,nRead); yPG\ &Bo
//if(nThreadID == 1) }.V0SM6
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); >@"3Q`
} IYg3ve`x
TxxB0
nk$V{(FJ
Utility.log("Thread " + nThreadID + " is over!"); o+Ti$`2<O7
bDownOver = true; ur,"K'w
//nPos = fileAccessI.write (b,0,nRead); bTy)0ta>AF
} <;0N@
catch(Exception e){e.printStackTrace ();} ';|>`<
} {^5<{j3e
} )k] !u
V3~a!k
8421-c6y>
//打印回应的头信息 jI2gi1,a
public void logResponseHead(HttpURLConnection con) bW.zxQ:
{ * r4/|.l
for(int i=1;;i++) ^'53]b:
{ SOQ-D4q
String header=con.getHeaderFieldKey(i); vp75u93
if(header!=null) 2n;;Tso"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); n.6 0$kR`
Utility.log(header+" : "+con.getHeaderField(header)); U2>dwn
else Fif^V
break; h)l&K%4;
} qb&NS4#
} eTRx6Fri(
<Bb<?7q$ld
fy=C!N&/
public void splitterStop() p2c=;5|/Q
{ $N+{r=
bStop = true; hB$Y4~T%
} m/c&/6nk
9_A0:S9Z
/xm#:+Sc
} U[e8K
kPX2e h
.6 ?>t!&W
/* 5v>{Z0TE[6
**FileAccess.java qwNKRqT
*//文件访问(定位，写) G9y12HV
package NetFox; dMs39j
import java.io.*; {F6dSF`
:n>ccZeMv
,dj*p,J
public class FileAccessI implements Serializable{ CVSsB:H6e
s@)"IdSA(
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 EfBVu
RandomAccessFile oSavedFile; !k= 0X\5L
long nPos; :_QAjU
['Y+z2k
|RAQ%VXm
public FileAccessI() throws IOException :CkR4J!m3
{ o=RqegL
this("",0); _`X#c-J
} 2hwXWTSu
"X{aS}
Y0u'@l_[F
public FileAccessI(String sName,long nPos) throws IOException 7fW=5wc
{ )Rhff$
oSavedFile = new RandomAccessFile(sName,"rw"); \abAPo
this.nPos = nPos; Q(;B)
oSavedFile.seek(nPos); OBw`!G*w
} [ 4Y `O
`k}l$ih`X
nc\C4g
public synchronized int write(byte[] b,int nStart,int nLen) ? __aVQ7
{ VM]GYz|#]
int n = -1; APtselC
try{ 7tfivIj)e
oSavedFile.write(b,nStart,nLen); ueE?"Hk
n = nLen; 4/`h@]8P
} A M1C $
catch(IOException e) 4I#eC#"
{ \Ul.K!b7
e.printStackTrace (); |DFvZ6}
} e@,u`{C[
:Hf0Qx6
QLB1:O>
return n; g<rKV+$6
} RFn0P)9&
VTJIaqw
i#]aV]IT
} 1t\b a1x
Z4HA94
D-o7yc"K
/* b,rH&+2H
**SiteInfoBean.java 2i7i\?<.
*/ s?@)a,C%k
package NetFox; <nb3~z1
$p0 /6c
DD@)z0W
public class SiteInfoBean { 0 .FHdJ<
1~R$$P11[9
R*Xu(89
private String sSiteURL; //Site's URL sMz^!RX@
private String sFilePath; //Saved File's Path ?}=-eJ(7e
private String sFileName; //Saved File's Name &'huS?gA9
private int nSplitter; //Count of Splited Downloading File J~iOP
W8G9rB|T
MS st
public SiteInfoBean() )H;pGM:
{//nSplitter的缺省值为5 C?w<$DU
//default value of nSplitter is 5 &$b\=
this("","","",5); TDAWI_83-
} .B 85!lCF
%K%^ ]{
q?imE~&U
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) r)6uX
{ e' U"`)S
sSiteURL= sURL; j!lAxlOX
sFilePath = sPath; y^mWG1"O
sFileName = sName; b(}Gm@#
this.nSplitter = nSpiltter; N;Z`%&
*?^Z)C>
Sg.+`xww3
} e$Xq
C5PmLiOHY>
4-7kS85
public String getSSiteURL() |RR%bQ^{
{ fjIcB+Z
return sSiteURL; _e?q4>B)c
} ]DC;+;8Jc
I!$jYY2
Ic[}V0dk
public void setSSiteURL(String value) i<4>\nc
{ pKt-R07*
sSiteURL = value; )YzHk ;(
} XMN?;Hj>
6o=qJ`m[?
JJ/1daj
public String getSFilePath() ,&.W6sW
{ Z0[)u_<
return sFilePath; ;dqk@@O"(
} JQ)4}t
JkSdLj
yaH Trh%
public void setSFilePath(String value) >aEL;V=}P
{ G3RrjWtO
sFilePath = value; dSOlD/c
} Fw_ (q!
KqM!!
May&@x/oMS
public String getSFileName() 4meidKw]
{ u(pdP"
return sFileName; 1Yc%0L(
} hD nM+4D
_\ .
Xh.+pJl,*
public void setSFileName(String value) I86e&"40
{ 8{R_6BS
sFileName = value; ! jbEm8bt
} _Kc1
J0^{,eY<
cPpu
public int getNSplitter() 5cD XWF
{ h [nH<m
return nSplitter; n?'d|h
} &EAk z
[096CK
]>tq|R78
public void setNSplitter(int nCount) 3g4e']t
{ `1nRcY
nSplitter = nCount; 9<xTu>7J
} BG'6;64kx6
} a @6^8B?w;
G/v|!}?wG
ds- yif6
/* SHMl%mw
**Utility.java _h0-
*/ c{1V.
package NetFox; ?22d},.
mfXD1]<.
`.{U-U\
public class Utility { ; D1FAz
pG/ NuImA
yh S#&)O
public Utility() WK pUn8&N
{ }<vvxi
Vy]A,Rn7
B,3 t`
} +0VG[c\8
A#<vG1
//线程睡眠 S8\+XJ
public static void sleep(int nSecond) `SCy<w3$+[
{ E@:Q 'g%
try{ TbOJp
Thread.sleep(nSecond); [}z?1Gj;W(
} IuNkfBe4m
catch(Exception e) e#tIk;9Xz
{ nz^nptw
e.printStackTrace (); XJe/tR
} E]NY (1
} GGH;Z WSe
#C4|@7w%
//日志 BsKbn@'uC
public static void log(String sMsg) p~h4\.*`
{ t)LU\!
System.err.println(sMsg); 0z/h+,
} g;8M<`qvf
1Yud~[c
Zp`~}LV{
public static void log(int sMsg) My. dD'C
{ C1 W>/?XC
System.err.println(sMsg); PC|'yAN:
} C5Xof|#p|
} 9qEOgJ
[6H}/_nD
]3}feU+
/* oew|23Ytb
**TestMethod.java A^-iHm
*/ %*6RzJO6
package NetFox; @: Z#E[N H
{(;B5rs
a2o.a2
public class TestMethod { >rKhlUD
zhX;6= X2
/9pbnzn
public TestMethod() X<Z(]`i
{ ///xx/weblogic60b2_win.exe _ \l HI
try{ K5{{:NR$
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QP:9%f>=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); .:8[wI_f
SiteFileFetch fileFetch = new SiteFileFetch(bean); mH)OB?+lq
fileFetch.start(); GMBJjP&R]
} }wfI4?}j}
catch(Exception e){e.printStackTrace ();} ^p,3)$
2 l(Dee Y
?~,JY
} gwiR/(1
Tv\HAK<N
~ 7}]
public static void main(String[] args) /_q#ah
{ M|k&TTV
new TestMethod(); to'j2jP
} %*jGim~s
} U+} y %3l
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