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)); Lw #vHNf6
} aG/L'weR
for(int i=0;i<nEndPos.length-1;i++) aT%6d@g
{ bY7~b/
nEndPos = nStartPos[i+1]; ^1w*$5YI
} @P}!mdH1
nEndPos[nEndPos.length-1] = nFileLength; s4Y7x.-
} BJ7m3[lz
} 'Lv>!s 7
"r.eN_d
ao.v]6a
//启动子线程 p+d?k"WN?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; k6W [//
for(int i=0;i<nStartPos.length;i++) ys$X!Ep
{ <bxp/#6D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +UC-
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), A]"IQ-
nStartPos,nEndPos,i); 1r;.r|
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <MoKTP-<
fileSplitterFetch.start(); @mrGG F
} LzJNQd'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !)TO2?,^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,mW-O!$3W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", F B7.b
nEndPos = " + nFileLength); 7Yd]#K{$
// fileSplitterFetch[nPos.length-1].start(); f1UGDC<p9
&nEQ`3~F
.f]2%utHB
//等待子线程结束 yu]nK-Y7S
//int count = 0; [X|KXlNfm
//是否结束while循环 !^<%RT9@|
boolean breakWhile = false; p(]o#$ 6[
aw8q}:
ia}V8i
while(!bStop) 74q|FQ
{ 7ZRLSq'S
write_nPos(); Ik74%x7G`
Utility.sleep(500); QnNddCiu=
breakWhile = true; 5 NdIbC
M]$_>&"
@G;\gJT*
for(int i=0;i<nStartPos.length;i++) 2 .)`8|c9
{ |=9=a@l]P
if(!fileSplitterFetch.bDownOver) -THU5AB
{ FlQ(iv)P
breakWhile = false; }c~o3t(7`b
break; -%#F5br%
} "G3zl{?GP
} 8o4?mhqV
if(breakWhile) S;FgS:;
break; JHZ`LWq
|ydOi&
>*aqYNft
//count++; 9F^rXY.
//if(count>4) UjI-<|
// siteStop(); G*lkVQ6?
} SYsbe 5j
?yqTLj
NN;'QiE
System.err.println("文件下载结束！"); urK[v
} =-U8^e_Y
catch(Exception e){e.printStackTrace ();} YKT=0
} ZhpbbS
Z#P:C":e
R8<'m
//获得文件长度 f~NGIlgR
public long getFileSize() YZH&KGY
{ D-IXO@x
int nFileLength = -1; BE]PM nI
try{ wkwsBi
URL url = new URL(siteInfoBean.getSSiteURL()); )+S^{tt
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~qxuD_
httpConnection.setRequestProperty("User-Agent","NetFox"); 9L^:N)-
+Y
)mVpJYt;
int responseCode=httpConnection.getResponseCode(); a9CK4Kg
if(responseCode>=400) P<<hg3@
{ !?~>f>js_l
processErrorCode(responseCode); >X"V
return -2; //-2 represent access is error L)Iv]u
} ;5fq[v^P:
4dwG6-
vtS[Tkk|A
String sHeader; Os# V=P
^cy.iolt
JM-rz#;1
for(int i=1;;i++) (?7=$z!h
{ M(_1'2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }.j09[<
//Utility.log(in.readLine()); RC| t-(Z
sHeader=httpConnection.getHeaderFieldKey(i); ZdP2}w
if(sHeader!=null) -Ob89Z?2A
{ pl{Pur ;i
if(sHeader.equals("Content-Length")) BbqH02i
{ #nS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j>70AE3[8
break; 1hQeuG
} tb@&!a$`?
} i!jR>+
else lrXi*u]
break; .^%!X!r
} _Bh ^<D-
} CQ+WBTiC
catch(IOException e){e.printStackTrace ();} *75?%l
catch(Exception e){e.printStackTrace ();} (t\ F>A
+80yyn#
]"Qm25`Qz
Utility.log(nFileLength); j5yxdjx9
9(PQ7}
#6%9*Rh
return nFileLength; uS%Y$v
} `T]1u4^E
-`o22G3w
8=#J:LeXj
//保存下载信息（文件指针位置） ma<+!*|
private void write_nPos() [e:mRMi
{ m:1f7Z>
try{ ??!+2G#%!
output = new DataOutputStream(new FileOutputStream(tmpFile)); FB-_a
output.writeInt(nStartPos.length); .Y"H{|]Mnh
for(int i=0;i<nStartPos.length;i++) KF#,Q
{ 3'H 1T
// output.writeLong(nPos); smM*HDK
output.writeLong(fileSplitterFetch.nStartPos); C)r!;u)AZH
output.writeLong(fileSplitterFetch.nEndPos); w/`I2uYu
} -m.SN>V
output.close(); 9ntXLWK7e
} 3 oG5E"G
catch(IOException e){e.printStackTrace ();} <opBOZ d
catch(Exception e){e.printStackTrace ();} $1h,<$5H
} ;&N;6V"}
cG"+n@\
qDQ$Zq[
//读取保存的下载信息（文件指针位置） )9L:^i6
private void read_nPos() 0pSqk/
{ X$L9kZ
try{ )@ /!B`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Lwg@*:`d
int nCount = input.readInt(); U2DE"
nStartPos = new long[nCount]; CCp8,
nEndPos = new long[nCount]; J1?)z+t9~
for(int i=0;i<nStartPos.length;i++) XL/?v" /
{ k|^e=I
nStartPos = input.readLong(); 1?6;Oc^
nEndPos = input.readLong(); X0,?~i6Q
} <4gT8kQ$x
input.close(); b`@aiXN)+
} RN0@Q~oTI
catch(IOException e){e.printStackTrace ();} ccUq!1
catch(Exception e){e.printStackTrace ();} 5/:BtlFx
} }4!R2c
~v2E<S3
+w ;2kw
private void processErrorCode(int nErrorCode) A{5^A)$
{ *20$u% z2
System.err.println("Error Code : " + nErrorCode); `Ns$HV
} ZYy,gu<
J!$q"0G'WT
,~@Nhd~k
//停止文件下载 ?F@0"qi
public void siteStop() hcvWf\4'#q
{ >i>%@
bStop = true; jXBAo
for(int i=0;i<nStartPos.length;i++) &TmN^R>
fileSplitterFetch.splitterStop(); #PzRhanX
Q0)6 2[cMm
kvzGI>H:
} q1Ja*=r
} ?h;Zdv>`xz
//负责部分文件的抓取 o<*H!oyP\
**FileSplitterFetch.java m"{D}(TA
*/ CH6^;.
package NetFox; _E[zYSo`
pNN6PsLt
GZ.Fq
import java.io.*; U*.Wx0QM
import java.net.*; pg\Ylk"T
Q3t9J"=1g
##gq{hgjb$
public class FileSplitterFetch extends Thread { a&6e~E$K2
JmJ8s hq
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String sURL; //File URL ,4bqjkX5q
long nStartPos; //File Snippet Start Position "T`Q,
long nEndPos; //File Snippet End Position <q V<dK&W
int nThreadID; //Thread's ID 28KS*5S
boolean bDownOver = false; //Downing is over a=<l}`*
boolean bStop = false; //Stop identical `u%`Nj
FileAccessI fileAccessI = null; //File Access interface c~B[<.Qj
&{):x
j4v.8;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ""GeO%J8
{ 9o|=n'o
this.sURL = sURL; !TJCQ[Aa}
this.nStartPos = nStart; v !~lVv&
this.nEndPos = nEnd; _b+=q:$/
nThreadID = id; jY>BU&
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~bSPtH ]6d
} GA,6G [E
lg)jc3
1gEeZ\B-&
public void run() 481SDG[b
{ dqU bJc]
while(nStartPos < nEndPos && !bStop) _5F8F4QY`
{ 0XCtw6
lx8@;9fLy
UenB4
try{ O7p>"Bh
URL url = new URL(sURL); [FHSFr E,5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q+ r4
httpConnection.setRequestProperty("User-Agent","NetFox"); 1(z&0Y;
String sProperty = "bytes="+nStartPos+"-"; vf=b5s(7Q
httpConnection.setRequestProperty("RANGE",sProperty); >wiW(Ki}
Utility.log(sProperty); I:4m]q b
$F|3VQ~
teO%w9ByY
InputStream input = httpConnection.getInputStream(); N? r{Y$x
//logResponseHead(httpConnection); `uz15])1<
$9pFRQC'q
`GsFvxz
byte[] b = new byte[1024]; Sm6hyZFy
int nRead; 1wX0x.4d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FL}k0
{ 6I0G.N
nStartPos += fileAccessI.write(b,0,nRead); *Uvh;d{
//if(nThreadID == 1) H1`}3}"
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); otQulL)T/
} *~~&*&+
2R:I23[#B
^l}Esz`-M
Utility.log("Thread " + nThreadID + " is over!"); N=e-"8
bDownOver = true; 6xk~Bt
//nPos = fileAccessI.write (b,0,nRead); v7?sXW
} }P8@\2@=T
catch(Exception e){e.printStackTrace ();} xh$1Rwa
} FdR!jt
} 3urL*Fw,
>syQDB
HmWU;9Vn+
//打印回应的头信息 h,-8( S
public void logResponseHead(HttpURLConnection con) tDF=Iqu)a
{ [42vO
for(int i=1;;i++) P`JO6O:&
{ kPt9(E]
String header=con.getHeaderFieldKey(i); yi7m!+D3
if(header!=null) Z x9oj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); g3r4>SA
Utility.log(header+" : "+con.getHeaderField(header)); ~NYy@l
else bo]xah|."j
break; #/u%sX`#y
} &/K:zWk3mx
} 7X\azL
}cov"o
}}AooziH9
public void splitterStop() aJ[K'5|
{ >j [> 0D
bStop = true; YzTmXwuA5
} F`W8\u'db
q9GSUkb
"I"(yiKD
} 35}{dr
Y7QIFY's~
O>YXvu
/* mTG v*=l
**FileAccess.java n9.` 5BH7/
*//文件访问(定位，写) ;J"b%~Gn
package NetFox; ( Z-~Eh
import java.io.*; 5r;M61
Ok7i^-85
cVrses^yE
public class FileAccessI implements Serializable{ e0i&?m
y'ZRoakz)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 u="VJ3
RandomAccessFile oSavedFile; 9EryHV|
long nPos; y/!h.[
a@[y)xa$Z
EAVB:gE
public FileAccessI() throws IOException Tvd=EO
{ Y9h~ hD
this("",0); x1\a_Kt
} <S*o}:iB
JgI+k Nx
5ZG-3qj
public FileAccessI(String sName,long nPos) throws IOException seT?:PCA
{ `^t0379e
oSavedFile = new RandomAccessFile(sName,"rw"); 3*13XQ
this.nPos = nPos; v!oXcHK/
oSavedFile.seek(nPos); 4~< :Pj
} &.sfu$]
M" |Mte
B+yr 6Q.
public synchronized int write(byte[] b,int nStart,int nLen) 577H{;pW
{ L;a>J
int n = -1; <"|BuK
try{ P{ AJH1
oSavedFile.write(b,nStart,nLen); 2jQ|4$9j
n = nLen; -J?i6BHb
} n@9*>DU
catch(IOException e) Z4U8~i
{ N O|&nqq,>
e.printStackTrace (); G.KZZ-=_4
} HtWuZq;w
Y<X,(\iEHP
y}NBJ
return n; O=wA/T=w?
} vM5u]u!
16q"A$
]=5nC)|
} ,U_p6TV5
T\g%.
3c<).aC0f
/* Y|bCbaF
**SiteInfoBean.java :-xF=Y(;
*/ S<Zb>9pl
package NetFox; Og8:
h#K863
:'-FaGy
public class SiteInfoBean { vas
;M '?k8L
Ip}(!D|
private String sSiteURL; //Site's URL u@v0I$
private String sFilePath; //Saved File's Path ~`Q8)(y<#$
private String sFileName; //Saved File's Name ^cO^3=
private int nSplitter; //Count of Splited Downloading File Q`#Y_N-h+
D]nVhOg|
PqMU&H_
public SiteInfoBean() i*`;/x'+
{//nSplitter的缺省值为5 2+pLDIIT
//default value of nSplitter is 5 Gq4~9Tm)*
this("","","",5); FyuCYg \p
} T7eo_Mn
>mzK96
a%2r]:?^?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K-VNU
{ MH{$"^K
sSiteURL= sURL; #`P4s>IL1
sFilePath = sPath; V9 <!pMj
sFileName = sName; %zg&eFRHI
this.nSplitter = nSpiltter; 31b9pi}nf
/JPyADi
"g7`Ytln
} .@{W6 /I
9N^&~O|1
zItf>j7|Z
public String getSSiteURL() $_,?SXM
{ SdF*"]t
return sSiteURL; so h3d
} Fxwe,
'\ec ,&4Z
2lw0'
public void setSSiteURL(String value) (r_xs
{ ,]e!OZ[$m
sSiteURL = value; /M>8ad
} 3^kZydZCN
7<&CN0&
|n-NK&Y(o
public String getSFilePath() %H\i}}PTe
{ LO8V*H(
return sFilePath; w]w>yD>$
} Lc;4 Hg
Cs$wgm*
=VkbymIZ4y
public void setSFilePath(String value) OZdiM&Zss
{ gf6<`+/
sFilePath = value; @;m7u
} /YYI 4
x6A*vP0nm)
7B GMG|
public String getSFileName() ,ZyTYD|7
{ <F!On5=W*
return sFileName; qG.HJD
} <TmMUA)`}
WlnmW(uahW
3P C'P2
public void setSFileName(String value) H:x=v4NgsU
{ r (Ab+1b
sFileName = value; +o)o4l%3
} E.kGBA;a?
MH|!tkW>:
)24r^21.q
public int getNSplitter() `mV&[`NZ
{ i,>yIPBU!
return nSplitter; (C/2shr 8
} ^]}UyrOn
fw@n[u{~
'6*^s&H~
public void setNSplitter(int nCount) 2<Lnfc<^k
{ 3A2X1V"
nSplitter = nCount; )F;`07
} >YuBi:z
} ^`NU:"
:Rc>=)<7
E[bJ5o**#
/* k4te[6)
**Utility.java .]`LR@qf
*/ 7a.$tT
package NetFox; ,a&N1G.
zg,?aAm
Rk8>Ak(/
public class Utility { a[iuE`
f Co-ony
Ht,_<zP;
public Utility() qh;ahX~
{ 4PUSFZK?
fMRBGcg7Dc
7!Z\B-_,
} -MZLkSU
6tXx--Nh
//线程睡眠 jt-Cy
public static void sleep(int nSecond) %(h-cuhq
{ }MAvEaUd
try{ a]^hcKo4
Thread.sleep(nSecond); K@lZuQ.1
} s"b()JP
catch(Exception e) Z_{`$nW
{ 1qXqQA
e.printStackTrace (); lquY_lrri
} ^Nl)ocHv!
} FWqnlK#
7g1"s1~or
//日志 cwiHHf>
public static void log(String sMsg) ;=piJ%k
{ Htn'(Q
System.err.println(sMsg); '6Dt@^-PZ
} N|pjGgI
S\2QZ[u
txM R[o_
public static void log(int sMsg) sU"D%G
{ %''z~LzJ8
System.err.println(sMsg); rug^_d=B
} K8CjZpzq
} `WvNN>R
(u`[I4z`
%/!n]g-
/* vq yR aaMf
**TestMethod.java S'~Zlv3`
*/ ~_v?M%5i
package NetFox; |&vQ1o|}
| _/D-m*
1(6B|w5+
public class TestMethod { tpw0j CVu
&>kklP
#;GIvfW
public TestMethod() /rp.H'hC
{ ///xx/weblogic60b2_win.exe Gxk=]5<7
try{ Qzy[
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V {R<R2h1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g _fvbVX
SiteFileFetch fileFetch = new SiteFileFetch(bean); xo#&&/6
fileFetch.start(); D6&fDhO27
} .ruGS.nS4
catch(Exception e){e.printStackTrace ();} /5M@>A^?'
\q#s/&b
z-(@j;.
} GFd~..$
-AwR$<q'
@@$=MSN
public static void main(String[] args) ]Cd1&
{ /VB n
new TestMethod(); yU"lW{H@
} X51pRP $R
} 7MIu-x|
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